Preset means set up or adjusted in advance, before you need to use it. When something is preset, someone has already configured it so it's ready to go without additional work.

Your alarm clock has a preset time, chosen the night before so it wakes you up automatically. A camera might have preset modes for different situations: one for portraits, another for action shots, and another for landscapes. Instead of manually adjusting dozens of settings, you just select the preset that matches what you're photographing.

Musicians use presets all the time. A keyboard might have preset sounds: press one button and it sounds like a piano, press another and it sounds like an organ. Recording software comes with preset effects that shape how voices or instruments sound, saving musicians from spending hours tweaking individual settings.

The word can also be a noun. When you save your favorite settings on a device, you're creating a preset. Video game players often customize their controls, then save those settings as a preset they can load instantly on any device.

Preset can also be a verb, meaning to set something in advance. You might preset the oven temperature before you start cooking, or preset a playlist to start at a certain time.

Presets save time and reduce complexity. Instead of starting from scratch every time, you use configurations that someone (maybe you, maybe the manufacturer) already tested and optimized. Preset is about preparation: doing the setup work once so the actual task becomes simpler and faster.