I have keys but no locks. I have a space but no room. You can enter, but can't go outside. What am I?

Why this works

This riddle plays on the multiple meanings of everyday words. The "keys" refer to the buttons on a keyboard that you press, rather than traditional keys that unlock doors. The "space" refers to the space bar on a keyboard, not a physical room. Finally, you can "enter" by pressing the enter key, but you can't physically go outside since it's an inanimate object. Each phrase cleverly describes aspects of a keyboard while evoking imagery that leads you to think of something more tangible.