What is the planet that has faint rings and is SOMETIMES the farthest planet from the sun?

The planet you are referring to is Neptune. Neptune is known for having faint rings, although they are not as prominent as the rings of Saturn. In terms of distance from the sun, Neptune is the farthest planet from the sun in our solar system most of the time. However, due to its elliptical orbit, it occasionally moves farther away from the sun than Pluto, making it the farthest planet from the sun during those periods.