"She [Jennifer] glanced over at a book case that took up most of the stairs. There was A Match Made In Space, the book Marty's father had written. Jennifer walked over to get a closer look, and saw that it wasn't a book at all — the label on its side said 'videobook' whatever that was. And just beyond that on the shelf were another half-dozen videobooks, all of them with neatly handwritten labels: / FAMILY VACATIONS — 1985-2005 / GEORGE & LORRAINE 50TH ANNIVERSARY / THE KIDS: MARTY JUNIOR AND MARLENE, VOL. 1 / THE KIDS: MARTY JUNIOR AND MARLENE, VOL. 2 / THE KIDS: MARTY JUNIOR AND MARLENE, VOL. 3 "
—From Back to the Future Part II by Craig Shaw Gardner (quote, page 66)

A videobook was a type of media used between 1985 and 2015.

The McFly family had videobooks of their family vacations, George and Lorraine's 50th anniversary, and of their children, Marty Jr. and Marlene. Existing books could also be made into videobooks, such as A Match Made in Space.