The ones with a hook in them are used for Snagging a fish by vertically dropping the weighted hook down and jerking it straight up.
Or "Tuna Jigs" as they are more commonly called.
The yellow ones are "Diamond" sinkers. Their shape will not allow them to get hung up on the bottom when you are fishing structure or
plunking eggs for fish, typically Salmon. Used tons of them when I lived in WA.