ABC are the first three letters of the Latin alphabet. They may refer to:
The timeline of world history details recorded events since the creation of writing roughly 5000 years ago (which marks the beginning of history) to the present day.
A timeline is a way of displaying a list of events in chronological order, sometimes described as a project artifact. It is typically a graphic design showing a long bar labeled with dates alongside itself and (usually) events labeled on points where they would have happened.
Timelines are often used in education to help students and researchers with understanding events and trends for a particular subject. A timeline is related to,[clarification needed] either one or all of the three, 1. the question or, that is, inquiry of when--one of the five Ws, 2. the subject or, that is, either concept or idea of time, and 3. the science of chronology.
Timelines are particularly useful for studying history, as they convey a sense of change over time. Wars and social movements are often shown as timelines. Timelines are also useful for biographies. Examples include:
Timelines are also used in the natural world and sciences for subjects such as astronomy, biology and geology.
Another type of timeline is used for project management. In these cases, timelines are used to help team members to know what milestones need to be achieved and under what time schedule. For example in the case of establishing a project timeline in the implementation phase of the life cycle of a computer system.
Those who cannot remember the past are condemned to repeat it.
History (from Greek ἱστορία - historia, meaning "inquiry, knowledge acquired by investigation") is the discovery, collection, organization, and presentation of information about past events. History can also mean the period of time after writing was invented. Scholars who write about history are called historians. It is a field of research which uses a narrative to examine and analyse the sequence of events, and it sometimes attempts to investigate objectively the patterns of cause and effect that determine events. Historians debate the nature of history and its usefulness. This includes discussing the study of the discipline as an end in itself and as a way of providing "perspective" on the problems of the present. The stories common to a particular culture, but not supported by external sources (such as the legends surrounding King Arthur) are usually classified as cultural heritage rather than the "disinterested investigation" needed by the discipline of history. Events of the past prior to written record are considered prehistory.
Station identification (Ident or Channel ID) is the practice of radio or television stations or networks identifying themselves on air, typically by means of a call sign or brand name (sometimes known, particularly in the United States, as a "sounder" or "stinger", more generally as a station or network ID). This may be to satisfy requirements of licensing authorities, a form of branding or a combination of both. As such it is closely related to production logos used in television and cinema, alike.
Station identification used to be done regularly by an announcer at the halfway point during the presentation of a television program, or in between programs.
Station identification in Australia is unlimited to the nominated common or on-air name of the station or network affiliation, both for radio and television.
A radio station may have call letters related to its town or district name, and the company name, hence Charters Towers, Queensland station 4CHT and Ceduna, South Australia's Ceduna Community Radio Inc's 5CCR; or, the station may have a name-callsign completely different from its license callsign, hence the Wollongong, New South Wales station licensed as 2UUL known on air as Wave FM.