Photo of residential water heater with copper flex lines and T&P drain line running down the side of the tank and mounted on a pedestal Anybody can install a water heater, but Kbeck does it right.
This one is has copper flex lines for easy access to the tank, if necessary, and a ball valve cold-water shutoff. Inexpensive gate valves are often used. Cheaper than ball valves, they are also more likely to fail years down the road when you might need them.
Actually, this was a re-installation under unusual circumstances. There had been a fire and it had burned through the floor. So we rebuilt the pedestal that's required by code and then reinstalled the water heater.
You might note also that this tank is properly earthquake-strapped, with heavy bands top and bottom bolted into boards that are in turn bolted into house studs. It is common to find no strap at all, or flimsy plumber's tape or straps of any sort screwed into plasterboard.
Earthquake strapping has been required by code since 1992 to lower the risk of a torn gas line and explosion in the event of earth movement.