What is writing in an active voice?

The active voice of a verb occurs in a sentence where the subject ('doer') of the action of the verb is also the grammatical subject of the verb. For example 'The boy ate the sandwich.' Here 'the boy' performs the action of eating, and is also the subject of the verb 'ate'.

In contrast, the passive voice occurs where the doer of the action of the verb is the grammatical object of the verb. For example 'The sandwich was eaten by the boy.' Here 'the boy' still performs the action of eating, but 'the sandwich' is the subject of the verb 'was eaten'.

'My mother always does the washing up.' (Active)

'The washing up is always done by my mother.' (Passive)