Short answers, pulled from the story.
Paul McCartney wrote the melody and first verse of Eleanor Rigby alone. The remaining lyrics were developed collaboratively at a session at John Lennon's home at Kenwood, with contributions from Harrison, Starr, and Lennon's friend Pete Shotton. McCartney estimated the split as 80-20 in his favour; Lennon later claimed larger shares, but eyewitness accounts from Pete Shotton and George Martin support McCartney as the principal author.
Eleanor Rigby appears on the Beatles' 1966 album Revolver, where it is the second track. It was also released simultaneously on the 5th of August 1966 as a double A-side single paired with Yellow Submarine.
Eleanor Rigby features only a string octet: four violins, two violas, and two cellos. None of the Beatles played instruments on the track, though McCartney, Lennon, and Harrison contributed vocals. The string arrangement was composed and conducted by producer George Martin, who drew inspiration from Bernard Herrmann's score for the 1960 film Psycho.
McCartney said "Eleanor" may have come from actress Eleanor Bron, who appeared with the Beatles in their 1965 film Help! The surname "Rigby" came from a shop in Bristol called Rigby and Evens Ltd, which McCartney noticed while visiting actress Jane Asher during her theatre run there in January 1966.
A headstone bearing the name Eleanor Rigby exists in the churchyard of St Peter's Parish Church in Woolton, Liverpool. The real Eleanor Rigby died in 1939 at the age of 44. McCartney said he had no memory of seeing the grave and attributed the match to his subconscious, maintaining that the character in the song is entirely fictional.
Eleanor Rigby topped singles charts in Australia, Belgium, Canada, New Zealand, and the UK, where it held the Record Retailer chart for four weeks as the band's eleventh number-one single. In the United States, it entered the Billboard Hot 100 in late August 1966 and peaked at number 11. The NME named it Single of the Year for 1966, and it won the Grammy for Best Contemporary Vocal Performance at the 9th Annual Grammy Awards in March 1967.