Shielding is the ability to create a force field around or in front of oneself for protection. This power has been displayed in Charmed though many various mediums and manifesting differently each time.
This is also one of Wyatt's powers, however this it manifests itself so that he can create a "bubble" rather than a wall of energy around him, in order to protect himself or somebody else, starting with his mother and later other characters, like his little brother Chris. It can also expand to repel people.
The only thing negative about this power is that demons and other beings can still transport Wyatt in his bubble when they work a huge amount of power on it, meaning that they need to use a lot of power to transport themselves and the bubble with Wyatt in it.