What is a "Filter" in an Image Editor?
A "filter" in an image editor is an effect that can be applied to an image, such as a filter to make it blurry, to make it less blurry, to make it gray scale, and so on. Filters are different from blend modes in that filters normally operate on a single layer's pixels rather than merging two layers together. Filters are usually destructive; non-destructive filters are called "adjustment layers" (Photoshop, Photopea), or "filter layers" (Krita).
