Have you ever drawn on a piece of paper with a white crayon and then painted over it with watercolors or markers? The places where you used the white crayon repel the paint or markers, and so the markings stay crisp and white while the rest of the paper gets colored.
This is kind of like resist dyeing! Resist dyeing is a way of coloring fabric, where parts of the fabric are "resisted" by a material or process, and so they resist being dyed. This means they stay their original color while the rest of the fabric changes color.
For example, if you wanted to make a pattern on a piece of fabric using resist dyeing, you might draw or paint a design onto the fabric with a special kind of wax or paste. When you then dye the fabric, the parts with wax or paste on them don't absorb the dye as much, so they stay lighter or even white, while everywhere else gets colored.
There are lots of different materials and techniques used in resist dyeing, from wax and paste to tying knots or folding the fabric in certain ways. Some cultures have been using resist dyeing techniques for centuries to create beautiful and intricate patterns on fabric for clothing, tapestries, and other uses.