Pull
Close-grip pull-ups place the hands very close on the bar (thumbs nearly touching), significantly changing muscular emphasis and pull angle. The short head of the biceps and the brachialis work harder, and the mid-back (rhomboids, mid traps) gets more stimulus than with a standard grip.
Pronated or supinated grip with hands very close. From a full hang, pull until the chin clears the hands. Elbows travel straight down (not out like standard pull-ups). Lower with control.
Many athletes find close-grip "easier" for lat activation but more demanding on the short biceps and brachialis. Excellent complement for the inner arm.
Very narrow grips can bother some wrists. If so, use a close neutral grip (multi-grip bars or rings).