A take profit is a way to tell your computer to get out of a trade automatically if it's won a certain amount. It will "take" the "profit" you have made. It is also sometimes called a Target.
When you create a pending order, you can set your entry, stop loss, and take profit. Essentially, you're telling the computer, "I want to get in here and then out here if I win and out here if I lose." This way, you can place the order and your account will do all those things automatically.
Your "take profit" will look like a horizontal dotted line on your chart.
For more definitions and trading terms please check out our Glossary.