Short answers, pulled from the story.
Allen Klein instigated the 1962, 1966 compilation album shortly before his dismissal from Apple Records in 1973. The project emerged as a direct response to bootleg albums flooding the market.
The Red Album deliberately omitted any George Harrison compositions from the era such as Taxman. Consequently the track list consists entirely of Lennon McCartney originals rather than the full breadth of their early output.
EMI announced on the 10th of August 2010 that the album would be remastered for a second time and released again as a two-CD package. This remastered version arrived worldwide on the 18th of October 2010 and reached North America one day later on the 19th of October 2010.
In the United States the album sold 1,215,338 LPs by the 31st of December 1973 and reached 5,475,942 copies by the end of that decade. The original double LP peaked at number 3 in the United Kingdom while topping the Cash Box albums chart in America.
Differences extended beyond packaging into the actual audio mixes used for specific tracks. The American edition included the same pseudo-James Bond intro found on the Help! soundtrack LP for the song Help whereas the British edition omitted that introduction entirely.