What are these two pipes next to faucets thet are capped on top and are about 12inches tall?

Hi Cber

They sound like old style water hammer arrestors (shock absorbers)... used to absorb the shock wave caused by quick closing valves like the solonoid valve at the dishwasher or washing machine connections. See image of them at an old shower valve below.

Some people still install them to this day although some argue they aren't needed at all and others install the more modern water hammer arrestors sold nowadays.

These older style "shock absorbers" can/will fail over time as the air inside them slowly gets displaced and the pipes fill with water. To "recharge" them, you should just need to drain the system for an hour or so to displace the water in the pipes and then refill the water pipes which will cause the pipes to refill with air... should last for years to come... ;)

Anything else?

Mark