Generally:
Raw Compiler: Converts pages of the original manga/manhwa/manhua/e.t.c. into files such as .png or .jpeg...if that makes sense hahahha.
Translator: Translates any language to English whilst retaining meaning of original language.
Proofreader: Reads over the translations. They correct the translations to follow English syntax and enforces readability/fluidity of translation of dialogue e.t.c.
Cleaner: Improves raw page quality via denoising, levelling and more. Can "clean" bubbles (use a brush and draw over the text in bubbles). Some groups consider "cleaners" the same as "redrawers".
Redrawers: Draws back original image that has been covered by text, such as watermarks or sound effects.
Typesetter: prints/typesets proofread translation into the cleaned/redrawn pages. They follow particular rules when typesetting. If you want the details, you can go to Scanlation School on Discord.
Editor: Are both redrawers and typesetters.
Quality Checker/Quality Control: Before uploading, they go through all the pages and enhances quality of scanlation by correcting mistakes that were caused by all the other roles. Like that junna said, they're the jack of all trades.
I probably repeated what everyone else said above lmaooo.