Sentences can be passive or active.

A sentence is written in the active voice when the subject of the sentence performs the action whereas in a sentence written in the passive voice, the subject will have the action acted upon by someone or something else instead.

Here is an example:

Active: The committee approved the new policy.
Passive: The policy was approved by the committee.

Watch the video below to learn the difference between the two and how to utilise them to improve your writing skills.