how do electronic cameras resemble photographic plates?

Question

how do they differ?

Answer 1

The most important similarity is that they are cumulative, which is why both photographic plates and CCDs are useful in astronomy. If you use them to photograph a faint star, you just give it a longer exposure. But no matter how long you stare at a faint star, it won't become visible. The most important practical difference is that unlike photographic plates, CCDs are reusable.