IP is shorthand for intellectual property, which covers a range of things that can include, but is not limited to, trademarks...
IP is shorthand for intellectual property, which covers a range of things that can include, but is not limited to, trademarks, copyrights and patents. An IP attorney is a lawyer who specializes in this particular area of law.
Intellectual property is a broad phrase that refers to things created by an individual but may not have a physical presence. Having IP laws in place is crucial to protecting/rewarding creators, while fueling innovation and creativity.