i have no idea what i'm doing

so this is my first build (already built it, love it) but i dont even know what overclocking is, or why i would do it. can someone help me understand overclocking and how to do it?

on a side note, is there anything i can do to make sure my games are running with the best graphics possible, other than the settings in the game?

CPU Intel Core i7-3770K 3.5GHz Quad-Core

CPU Cooler Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing

Motherboard Asus P8Z77-V LK ATX LGA1155

Memory Corsair XMS 16GB (2 x 8GB) DDR3-1333

Storage Western Digital Caviar Black 1TB 3.5" 7200RPM

Video Card Asus Radeon HD 7950 3GB

Case Inwin Dragon Rider ATX Full Tower

Power Supply Xion 850W ATX

Optical Drive Lite-On iHAS124-04 DVD/CD Writer

Operating System Microsoft Windows 7 Home Premium SP1 (OEM) (64- bit)