Bracelets are jewelry for your wrist, including watches. (We don't have watches... yet.)
The typical bracelet is a cuff bracelet, which has an opening that lets you slide your wrist into the bracelet. These are usually designed to fit snugly on the arm and not move around.
A bangle is a bracelet that is rigid like a cuff, but unlike a cuff the material is present all the way around the bracelet. They might have a hinge to make easier to put on the bangle, but usually they are sized large enough to fit a hand through. They are usually designed to hang at the wrist, and move around as they are worn.
A chain bracelet has interconnected links making up the length of the bracelet, and the ends have the two halves of a clasp. Generally speaking, these are loose fitting bracelets.
Linked metal bracelets often have stones set in metal bezels, and the bezels are linked together. The length might be adjustable, allowing for your preference in fit to shine through.