What does recto verso mean?

When a page is printed recto verso, this means that there is printing on both sides of the paper.

The meaning of recto verso

Recto stands for front, the page that is printed first, and verso for back, the page that is printed next. For example, a flyer is almost always printed recto verso.

When looking at an open book, the right page is the recto side. The left page is the verso side.