What is the meaning of Sandbox?

A children's play area consisting of a box filled with sand.

A box filled with sand that is shaped to form a mould for metal casting.

A container for sand or pounce, used historically before blotting paper.

An animal's litter box.

A box carried on locomotives, from which sand runs onto the rails in front of the driving wheels, to prevent slipping.

An isolated area where a program can be executed with a restricted portion of the resources available.

A page on a meaning where users are free to experiment without destroying or damaging any legitimate content.

The Middle East.

To restrict (a program, etc.) by placing it in a sandbox.

To brainstorm; to prototype.

Source: wiktionary.org