Phineas and Ferb is an American animated television comedy-musical series. Originally broadcast as a preview on February, 2007, on Disney Channel, the series follows Phineas Flynn and his English stepbrother Ferb Fletcher on summer vacation. Every day, the boys embark on some grand new project, which annoys their controlling sister, Candace, who frequently tries to reveal their shenanigans to her and the boys' mother, Linda Flynn-Fletcher, and less frequently to their father, Lawrence Fletcher. The series follows a standard plot system; running gags occur every episode, and the B-Plot almost always features Perry the Platypus acting as a secret agent ("Agent P") for the OWCA (Organization Without a Cool Acronym), to fight an evil scientist named Dr. Heinz Doofenshmirtz. The two plots intersect at the end to erase all traces of the boys' project just before Candace can show it to their mother. This usually leaves Candace very frustrated.
Source: Wikipedia, "Phineas and Ferb," available under the CC-BY-SA License.