An entry is a one line text editor. It is typically used to obtain textual input from user, such as a file name.
To enter text into an entry the user moves the pointer into the entry, causing the entry to take focus and making a red cursor to appear. The user can then enter characters and they will be inserted at the point of the cursor. The cursor can be moved by clicking mouse button 1 anywhere in the entry's text. Text in an entry can be selected by pressing and dragging mouse button 1. Selections can be pasted into an entry by pressing mouse button 2 in the entry. The entry widget supports a few emacs like editing commands.
When a return key or the tab key is pressed in an entry, and if it has callbacks, the callbacks are invoked.