Mutable means: 1) You can turn down the volume during the commercials
2) The data in question can be changed.
3) A button on your remote control.
4) The ability to synchronize two threads after a period of time.

2) The data in question can be changed.

Explanation:

Mutable objects are those objects that can be changed after they are created, and they can store a a large collection of data. Mutable objects are more flexible for programming as they are easily modifiable. The limitation of mutable object is that, only the copy of the object, and not the original object is mutable. This may lead to unexpected bugs in the code.