Short answers, pulled from the story.
The term record label derives directly from the circular paper stuck to the center of a vinyl record. This physical artifact served as the primary identifier for the brand associated with music recordings and music videos.
The Big Four entities include Sony Music Entertainment, Universal Music Group, Walt Disney Records, and Warner Music Group. These corporations controlled between 65 and 70 percent of the world market for the sale of records and music videos in 2014.
Independent labels operate outside the control of the big four and are defined by their independence from major music groups. These labels often offer larger artist royalties and may use a 50-50 profit-share agreement to allow artists to retain more of their earnings.
Prince engaged in a much-publicized feud with Warner Bros. Records from 1994 to 1996. This conflict involved disputes over ownership and control of his music, leaving him in a state of limbo while the label prevented the release of his music for years.
A 360 deal is a type of contract where labels are given rights and percentages to an artist's touring, merchandising, and endorsements. In exchange for these rights, labels usually give higher advance payments to artists and have more patience with artist development.
An imprint is a label used as a trademark or brand that often operates as a pseudonym for a parent label without a distinct business structure. A sublabel refers to either an imprint or a subordinate label company, such as 4th & B'way Records, which was a trademarked brand owned by Island Records Ltd.