Can you explain how to connect a type 7812 voltage regulator ic?

A Type 7812 voltage regulator ic (integrated circuit) is 3-terminal device with separate pins for Input, Output and Ground.

Basically you connect a suitable source (a battery or a power supply unit that plugs into the house's main electricity service) to the Input pin and the Ground pin. Connect your load device (the equipment which requires a regulated voltage) to the Output pin and the Ground pin.

You can find circuit diagrams for using this type of voltage regulator IC in electronics textbooks and often in the catalogs produced by suppliers of electronic components.

For technical and licensing reasons circuit diagrams cannot be included within the answers on this site.

The Related Link shown below gives detailed information about the ic itself, including its own internal circuit diagram.