Definition - The area of the court between the baseline and the service line.
After returning a serve or a groundstroke with no plans of going into the net to volley, move back at least one step behind the baseline. From this position, you will not have to make a difficult deep court volley, and also, you will be absolutely clear on which balls are going in or out. Having to hit a half-volley that deep in the court is usually a losing proposition.
After returning a serve or groundstroke with the idea of attacking and going toward the net to volley, move in to a spot approximately ONE STEP INSIDE THE SERVICE LINE. This prevents so many balls from landing at your feet.
Remember, all players must learn to play in "No Man's Land." But the secret is to just hit one ball there. If you hit a ball from "No Man's Land" and do not wish to go to the net, then move back one step behind the baseline. If you hit a ball from "No Man's Land" and wish to go to the net, then move up quickly at least one step inside the service line. The most frequent club level mistake is staying in "No Man's Land" too long.