A more thorough explanation:

Revocation of Will by Act is a legal term that means a person can cancel their will by doing something that shows they no longer want it to be valid. To revoke a will, the person must have the intention to cancel it and take action to do so. This can be done by burning, tearing, cancelling, obliterating, or destroying the will.

For example, if someone tears up their will and throws it away, they are revoking it by act. Another example is if someone burns their will, they are also revoking it by act. These actions show that the person no longer wants their will to be valid.

It's important to note that simply talking about revoking a will is not enough. The person must take physical action to cancel it.