You know how mighty/powerful  these guys are and their influence on ones Birthchart?
Are they just imaginary points in the sky ? yeah they are ! but effects are damn real  !
You cant imagine ;)
So what exactly are They?
Ecliptic plane is a plane where Earth revolves around the Sun.
Naturally , when moon revolves around earth intersects ecliptic plane in exactly two points .
Upper point as moon seems to be going Up  the plane called Rahu & Lower points as moon seems to going down the plane called Ketu.
whenever there is eclipse moon, earth,sun in a line so as rahu/ketu also.eclipse has special importance hence rahu/ketu also .
hence thay have given status of Planets .
Position of Rahu/ketu  in one Birthchart has significant effect on one's life.
They also called as "Chhaya Graha" (Shadowy planets).
Rahu also known as Dragon's Head
Ketu also known as Dragon's Tail.