Short answers, pulled from the story.
The First Folio is a 1623 collection of 36 plays by William Shakespeare, formally titled Mr. William Shakespeare's Comedies, Histories, and Tragedies. It was compiled by Shakespeare's colleagues John Heminges and Henry Condell and published about seven years after Shakespeare's death on the 23rd of April 1616.
Of approximately 750 copies believed to have been printed, 235 are known to survive. More than one third of these, 82 copies, are held at the Folger Shakespeare Library in Washington, D.C.
Eighteen plays in the First Folio had never been printed before 1623, including The Tempest, Twelfth Night, Macbeth, Julius Caesar, Measure for Measure, and Antony and Cleopatra. Without the Folio, these texts might have been lost entirely.
Jean-Christophe Mayer estimates the original retail price at about 15 shillings for an unbound copy and up to one pound for a calfskin-bound copy. A bound copy represented nearly two months' wages for an ordinary skilled worker of the time.
The First Folio was printed by William Jaggard and his son Isaac. William Jaggard had previously published The Passionate Pilgrim under Shakespeare's name without permission and in 1619 had printed new editions of ten Shakespearean quartos with false dates and title pages. Shakespeare was reportedly much offended by Jaggard's earlier conduct.
A copy sold by Mills College at Christie's in October 2020 fetched $10 million, making it the most expensive work of literature ever auctioned at that time. A separate copy had sold at Christie's in New York in October 2001 for a hammer price of $6.16 million.