Short answers, pulled from the story.
The British Market Research Bureau began compiling data for what would become the official UK charts in 1969. This organization operated until 1983 when Gallup took over the responsibility of gathering sales figures from retailers across the country.
On the 5th of September 2008, the organization officially rebranded itself as the Official Charts Company while introducing a fresh logo design. Later iterations dropped the word Company entirely leaving just Official Charts as the public-facing brand name.
Starting in January 2017, one hundred fifty streams count as equal to one single sale on the Official Charts Company Top 40. By June 2017 additional rules kicked in where tracks declining for three consecutive weeks after ten weeks on the chart see their stream-to-sale ratio jump to three hundred to one.
In 2017 the company signed an agreement with the Irish Recorded Music Association to compile Ireland's official singles and albums charts. The transition became effective the 1st of January 2021 when they took over French music chart contracts from German firm GfK for Syndicat National de l'Édition Phonographique.
Five representatives from record companies sit alongside five retailers on the Chart Supervisory Committee that decides all rule changes for the organization. Major label corporations WMG Sony Music and UMG provide record company voices while BMG Rights Management and PIAS Group represent large independent labels.