The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.
Earthquakes are related to tectonic activities because of the plates sliding past each other. This process is called a passive plate boundary. The plates are moved due to convection currents
Jupiter's moons are orbiting Jupiter while Jupiter's position doesn't change. Each day, there are some moons visible, while others are hidden behind Jupiter.
