The LM7805 is a voltage regulator IC that outputs +5 volts.
Like most other regulators in the market, it is a three-pin IC; input pin for accepting incoming DC voltage, ground pin for establishing ground for the regulator, and output pin that supplies the positive 5 volts.
 
Product Features:
3-Terminal Regulators
Output Current up to 1.5A
Internal Thermal-Overload Protection
High Power-Dissipation Capability
Internal Short-Circuit Current Limiting
Output Transistor SAFE-Area Compensation