A proxy is someone or something authorized to act on behalf of another person.

If your mom can't attend a parent-teacher conference, she might send your dad as her proxy to hear what the teacher says and make decisions. In a club election, if you're sick on voting day, you might give your voting rights to a friend who acts as your proxy, casting a vote according to your wishes. Companies use proxies when shareholders can't attend meetings in person but still want their votes counted on important decisions.

The word also refers to something that stands in for or represents something else. Scientists might use tree rings as a proxy for historical climate data, since the thickness of rings indicates how much rain fell in past years. A teacher might use quiz scores as a proxy for understanding, assuming that good scores reflect genuine comprehension.

In computer networks, a proxy server acts as an intermediary between your computer and the internet, handling requests on your behalf. This can provide security, privacy, or faster access to information.

The key idea: a proxy acts with delegated authority or serves as a stand-in, representing the real thing when the real thing can't be present or directly measured.