Nikon D750 DSLR Camera (Body Only) - Manual (Page 148)

120
Focus
This section describes the focus options available when
photographs are framed in the viewfinder. Focus can be
adjusted automatically (see below) or manually (
0 132). The
user can also select the focus point for automatic or manual
focus (
0 127) or use focus lock to focus to recompose
photographs after focusing ( 0 129).
To use autofocus, rotate the
focus-mode selector to
AF .
Autofocus
Focus-mode selector