The difference between pipes and tubes is simply in the way it is sized. PVC pipe for plumbing applications and galvanized steel pipe for instance, are measured in IPS (iron pipe size). Copper tube, CPVC, PeX and other tubing is measured nominally, which is basically an average diameter. These sizing schemes allow for universal adaptation of transitional fittings. For instance, 1/2" PeX tubing is the same size as 1/2" copper tubing. 1/2" PVC on the other hand is not the same size as 1/2" tubing, and therefore requires either a threaded male or female adapter to connect them. When used in agricultural irrigation, the singular form "pipe" is often used as a plural.
A leaky faucet can be a relatively easy fix depending on the type of faucet, so get to know the basic types of faucets and how to take them apart. You can look for instructions online; YouTube videos are the most useful. A slow drip usually means that all you have to replace is a washer, but make sure you know which size you need before buying a new one.