What is the point of a filibuster?

To delay or prevent a vote on any given matter.

Elaborate:

Derived from the Dutch term meaning ‘robber’, the filibuster, in the US, forces a debate into long hours as a member of senate invokes the policy of ‘unlimited debate’ to drone on and test his bladder skills while disallowing any progress to be made.

Senate rules permit a senator, or series of senators, to speak for as long as they wish and on any topic they choose, unless “three-fifths of the Senators duly chosen and sworn” (usually 60 out of 100 senators) brings debate to a close by invoking cloture under Senate Rule XXII.

Mitt Romney Pisses Himself During Filibuster

Reason For Asking:

I had understood what a filibuster was, literally, but it seemed like too much of a childish action to be taken as seriously as it is in the Senate.

Source: Wikipedia: Filibuster
Source: PolicyMic: Filibuster