William Collins, Sons

William Collins, Sons & Co., often referred to as Collins, was a Scottish printing and publishing company founded by a Presbyterian schoolmaster, William Collins, in Glasgow in 1819, in partnership with Charles Chalmers, the younger brother of Thomas Chalmers, the minister of Tron Church in Glasgow. Collins merged with Harper & Row in 1990, forming a new publisher named HarperCollins.

From the Wikipedia article “William Collins, Sons”, licensed under CC BY-SA 4.0.

An imprint is a brand inside a larger publishing house, often with its own editors and list. Imprints of large groups usually acquire through literary agents; read recent titles to see whether your book fits the list, then target agents who sell to it.