Terrestrial and telluric are from the Latin words for Earth (Terra and Tellus) because these planets composition is similar to that of the Earth.
The four terrestrial planets are (in order of distance from the Sun): Mercury, Venus, Earth, and Mars. Other than Earth, it is believed that the conditions on Mars are the most hospitable for life. It may have had life there in the past, and there may still be life on Mars today. The extreme conditions on Mercury and Venus are too harsh to sustain and nurture life.
Relative distance of the inner planets from the Sun
Facts about the terrestrial (inner) planets
To find out more about each of the terrestrial planets in our solar system, click one below for facts and information on them.