In Niels Bohr's model of the atom, electrons move

they move in an orbit of a fixed size and also energy

the electrons move by describing circular orbits around the nucleus.

Explanation:

The main characteristic of the Bohr model is that the electrons are located around the nucleus at certain determined distances. Bohr's model is simple and similar to Copernicus' planetary model, where the planets describe circular orbits around the Sun. The electron in an atom describes circular orbits, but the radii have fixed values.