Cell was created from the cells of many powerful warriors, meaning he can unleash all of people like Goku and Piccolo's best techniques at will!

Goku's signature technique, the user focuses their energy into the palms of their hands and then releases it in a single, powerful attack.
The version of this attack that Cell uses in his final battle against Gohan had enough power to blow away the entire solar system.

Regeneration

This ability allows the user to regenerate and heal damage dealt to their body.
Cell gained access to this power thanks to Piccolo's cells.

Barrier

This technique projects an energy field to protect the user from enemy attacks.
Cell nullifies Goku's Ki blasts by extending this barrier outwards from his body.

(Tale 402)

Cell Jr. Creation

Cell can create a swarm of Cell Jrs. from his tail and command them to attack his foes.
Each Cell Jr. was more than a match for even powerful warriors like Trunks and Vegeta.

Self-Destruct

Cell is able to swell up his body like a monstrous beachball and then explode.
He tried to use this technique to obliterate not only Gohan and his friends but the entire planet Earth as well.

(Tale 412)

Teleportation

The user locks onto an individual's Ki, then instantly teleports to their location.
Cell learned this technique after Goku used it to transport the two of them to the Planet of the Kaio just before he self-destructed.

(Tale 413)