Linear encoder

A linear encoder is like a little ruler that measures how far something moves in a straight line. You know how when you draw a picture on a piece of paper, you can use a ruler to draw straight lines? Well, a linear encoder is like that ruler, but it's really, really precise!

Here's how it works: there's a little sensor that sits at one end of the linear encoder, and a small strip of metal or plastic with lines on it that sits at the other end. When the thing you want to measure moves, it slides along the strip of metal or plastic, and the sensor reads the lines and tells you exactly how far the thing moved.

This is really useful if you need to know something's position very precisely -- like if you're making a machine that needs to move things really, really accurately. You can use a linear encoder to tell the machine precisely where it is, so it can do things like cut or drill with super accuracy.

Overall, a linear encoder is like a super precise ruler that measures how far things move in a straight line.