The terms Anno Domini (AD) and Before Christ (BC) are used when designating years in the Gregorian and Julian calendars. The term anno Domini is Medieval Latin and means "in the year of the Lord" but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "anno Domini nostri Jesu Christi", which translates to "in the year of our Lord Jesus Christ". The form "BC" is specific to English, and equivalent abbreviations are used in other languages: the Latin form, rarely used in English, is ante Christum natum (ACN) or ante Christum (AC).

This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus, AD counting years from the start of this epoch and BC denoting years before the start of the era. There is no year zero in this scheme; thus the year AD 1 immediately follows the year 1 BC. This dating system was devised in 525 by Dionysius Exiguus but was not widely used until the 9th century.

Terminology that is viewed by some as being more neutral and inclusive of non-Christian people is to call this the Common Era (abbreviated as CE), with the preceding years referred to as Before the Common Era (BCE). Astronomical year numbering and ISO 8601 avoid words or abbreviations related to Christianity, but use the same numbers for AD years (but not for BC years in the case of astronomical years; e.g., 1 BC is year 0, 45 BC is year -44).

Geologic Time: Period prior to humans. 4.6 billion to 3 million years ago

Primatomorphid Era: Period prior to the existence of Primatomorpha

Simian Era: Period prior to the existence of Simiiformes

Hominoid Era: Period prior to the existence of Hominoidea

Hominid Era: Period prior to the existence of Hominidae

• Distant signs of Human-like apes

Homininaeid Era: Period prior to the existence of Homininae

Homininid Era: Period prior to the existence of Hominini

Prehistory: Period between the appearance of Homo ("humans"; first stone tools c. three million years ago) and the invention of writing systems (for the Ancient Near East: c. five thousand years ago).

Paleolithic: Period that extends from the earliest known use of stone tools by hominins, c. 3.3 million years ago, to the end of the Pleistocene, c. 11,650 cal BP.

Lower Paleolithic: time of archaic human species, predates Homo sapiens. It spans the time from around 3.3 million years ago when the first evidence for stone tool production and use by hominins appears in the current archaeological record, until around 300,000 years ago, spanning the Oldowan and Acheulean lithics industries.

Middle Paleolithic: coexistence of archaic and anatomically modern human species. The Middle Paleolithic broadly spanned from 300,000 to 50,000 years ago.

Upper Paleolithic: worldwide expansion of anatomically modern humans, the disappearance of archaic humans by extinction or admixture with modern humans; earliest evidence for pictorial art. Very broadly, it dates to between 50,000 and 12,000 years ago (the beginning of the Holocene), according to some theories coinciding with the appearance of behavioural modernity in early modern humans, until the advent of the Neolithic Revolution and agriculture.

Mesolithic (Epipaleolithic): The Mesolithic (Greek: μέσος, mesos 'middle' + λίθος, lithos 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymously, especially for outside northern Europe, and for the corresponding period in the Levant and Caucasus. The Mesolithic has different time spans in different parts of Eurasia. It refers to the final period of hunter-gatherer cultures in Europe and the Middle East, between the end of the Last Glacial Maximum and the Neolithic Revolution. In Europe it spans roughly 15,000 to 5,000 BP; in the Middle East (the Epipalaeolithic Near East) roughly 20,000 to 10,000 BP. The term is less used of areas farther east, and not at all beyond Eurasia and North Africa.

Neolithic: The Neolithic or New Stone Age (from Greek νέος néos 'new' and λίθος líthos'stone') is an archaeological period, the final division of the Stone Age in Europe, Asia, Mesopotamia and Africa (c. 10,000 BC to c. 2,000 BC). It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of settlement. The term 'Neolithic' was coined by Sir John Lubbock in 1865 as a refinement of the three-age system.

Chalcolithic (or "Eneolithic", "Copper Age"): still largely Neolithic in character, when early copper metallurgy appeared alongside the use of stone tools. The transition from Copper Age to Bronze Age in Europe occurred between the late 5th and the late 3rd millennium BC.

Bronze Age: not part of prehistory for all regions and civilisations who had adopted or developed a writing system. The Bronze Age was a historical period lasting from approximately 3300 to 1200 BC. It was characterized by the use of bronze, the use of writing in some areas, and other features of early urban civilisation. The Bronze Age is the middle principal period of the three-age system, between the Stone and Iron Ages.

Ancient Egypt: Ancient Egyptian civilisation coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first king of the First Dynasty, Narmer. Predominantly native Egyptian rule lasted until the conquest by the Achaemenid Empire in the sixth century BC.

Iron Age: not part of prehistory for all civilisations who had introduced written records during the Bronze Age. In Anatolia and the Caucasus, or Southeast Europe, the Iron Age began during the late 2nd millennium BC (c.1300 BC). In the Ancient Near East, this transition occurred simultaneously with the Late Bronze Age collapse, during the 12th century BC (1200-1100 BC).

Ancient History: Aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly five thousand years, beginning with the earliest linguistic records in the third millennium BC in Mesopotamia and Egypt.

Classical Antiquity: Broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world. It is the period in which Greek and Roman society flourished and wielded great influence throughout Europe, North Africa and the Middle East.

Post-classical History: Period of time that immediately followed ancient history. Depending on the continent, the era generally falls between the years AD 200-600 and AD 1200-1500. The major classical civilizations that the era follows are Han China (ending in 220), the Western Roman Empire (in 476), the Gupta Empire (in the 550s), and the Sasanian Empire (in 651).

Middle Ages: Lasted from the 5th to the 15th century. It began with the collapse of the Western Roman Empire in 476 and is variously demarcated by historians as ending with the Fall of Constantinople in 1453, or the discovery of America by Columbus in 1492, merging into the Renaissance and the Age of Discovery.

Modern History: After the post-classical era

Early Modern Period: The chronological limits of this period are open to debate. It emerges from the Late Middle Ages (c. 1500), demarcated by historians as beginning with the fall of Constantinople in 1453, in forms such as the Italian Renaissance in the West, the Ming dynasty in the East, and the rise of the Aztecs in the New World. The period ends with the beginning of the Age of Revolutions.

BP: Stands for "Before Present" or "Years Before Present" (YBP). It specifies when events occured before 1 January 1950, the conventional date for the start of radiocarbon dating.

The Industrial Revolution, sometimes divided into the First Industrial Revolution and Second Industrial Revolution, was a period of global transition of the human economy towards more widespread, efficient and stable manufacturing processes that succeeded the Agricultural Revolution. Beginning in Great Britain, the Industrial Revolution spread to continental Europe and the United States, from around 1760 to about 1820-1840. This transition included going from hand production methods to machines; new chemical manufacturing and iron production processes; the increasing use of water power and steam power; the development of machine tools; and the rise of the mechanised factory system. Output greatly increased, and the result was an unprecedented rise in population and the rate of population growth. The textile industry was the first to use modern production methods and textiles became the dominant industry in terms of employment, value of output, and capital invested.

Many of the technological and architectural innovations were of British origin. By the mid-18th century, Britain was the world's leading commercial nation controlling a global trading empire with colonies in North America and the Caribbean. Britain had major military and political hegemony on the Indian subcontinent; particularly with the proto-industrialised Mughal Bengal, through the activities of the East India Company. The development of trade and the rise of business were among the major causes of the Industrial Revolution. Developments in law also facilitated the revolution, such as courts ruling in favour of property rights. An entrepreneurial spirit and consumer revolution helped drive industrialisation in Britain, which after 1800, was emulated in Belgium, the United States, and France.

The Industrial Revolution marked a major turning point in history, comparable only to humanity's adoption of agriculture with respect to material advancement. The Industrial Revolution influenced in some way almost every aspect of daily life. In particular, average income and population began to exhibit unprecedented sustained growth. Some economists have said the most important effect of the Industrial Revolution was that the standard of living for the general population in the Western world began to increase consistently for the first time in history, although others have said that it did not begin to improve meaningfully until the late 19th and 20th centuries. GDP per capita was broadly stable before the Industrial Revolution and the emergence of the modern capitalist economy, while the Industrial Revolution began an era of per-capita economic growth in capitalist economies. Economic historians agree that the onset of the Industrial Revolution is the most important event in human history since the domestication of animals and plants.

The precise start and end of the Industrial Revolution is still debated among historians, as is the pace of economic and social changes. According to Cambridge historian Leigh Shaw-Taylor, Britain was already industrialising in the 17th century, and "Our database shows that a groundswell of enterprise and productivity transformed the economy in the 17th century, laying the foundations for the world's first industrial economy. Britain was already a nation of makers by the year 1700" and "the history of Britain needs to be rewritten”. Eric Hobsbawm held that the Industrial Revolution began in Britain in the 1780s and was not fully felt until the 1830s or 1840s, while T. S. Ashton held that it occurred roughly between 1760 and 1830. Rapid adoption of mechanized textiles spinning occurred in Britain in the 1780s and high rates of growth in steam power and iron production occurred after 1800. Mechanised textile production spread from Great Britain to continental Europe and the United States in the early 19th century, with important centres of textiles, iron and coal emerging in Belgium and the United States and later textiles in France.

An economic recession occurred from the late 1830s to the early 1840s when the adoption of the Industrial Revolution's early innovations, such as mechanised spinning and weaving, slowed as their markets matured; and despite the increasing adoption of locomotives, steamboats and steamships, and hot blast iron smelting. New technologies such as the electrical telegraph, widely introduced in the 1840s and 1850s in the United Kingdom and the United States, were not powerful enough to drive high rates of economic growth.

Rapid economic growth began to reoccur after 1870, springing from a new group of innovations in what has been called the Second Industrial Revolution. These included new steel-making processes, mass production, assembly lines, electrical grid systems, the large-scale manufacture of machine tools, and the use of increasingly advanced machinery in steam-powered factories.

As the first industrial nation, the movement of people from a rural environment, to work in factories in cities, would change the genetic profile of Britain and consequently the rest of the world.