The term high definition once described a series of television systems originating from August 1936; however, these systems were only high definition when compared to earlier systems that were based on mechanical systems with as few as 30 lines of resolution. The ongoing competition between companies and nations to create true "HDTV" spanned the entire 20th century, as each new system became more HD than the last.In the beginning of the 21st century, this race has continued with 4k, 5k and current 8K systems.
During which entire century were companies and nations trying to achieve true HDTV?
20th

Broadcasters were faced with having to adapt daily to the varied recording characteristics of many sources: various makers of "home recordings" readily available to the public, European recordings, lateral-cut transcriptions, and vertical-cut transcriptions. Efforts were started in 1942 to standardize within the National Association of Broadcasters (NAB), later known as the National Association of Radio and Television Broadcasters (NARTB). The NAB, among other items, issued recording standards in 1949 for laterally and vertically cut records, principally transcriptions. A number of 78 rpm record producers as well as early LP makers also cut their records to the NAB/NARTB lateral standard.
Which recording types were effected by the imposed industry standards?
laterally and vertically cut records, principally transcriptions.

Indigenous Australians have been referred to as "black people" in Australia since the early days of European settlement. While originally related to skin colour, the term is used to today to indicate Aboriginal or Torres Strait Islander ancestry in general and can refer to people of any skin pigmentation.
What was the original term related to?
skin colour