If you do something of your own volition, you choose to do it because you want to—not because you are forced to.
A malevolent person or thing is evil due to deliberate attempts to cause harm.
Someone who is benevolent wishes others well, often by being kind, filled with goodwill, and charitable towards them.
If a task or job is voluntary, you can choose whether or not you want to do it; it is a type of work for which you do not get paid.
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