The differences between newts and salamanders are really minor, newts are a group of salamanders (or I should say a newt is a type of salamander), so it is correct to say that some salamanders are also newts. Newts usually have rougher skin than other salamanders (at least not as slimy), and most newts return to an aquatic habitat for their adult life (or at least part of it). The pacific newts (genus Taricha) are terrestrial as adults, but return to water to breed, during the breeding season, they develop a flat tail, which is another of the “differences” between the two types, (salamanders have round tails).
Salamanders are predators, most eat insects, earthworms and spiders, but some will also eat small mammals and other amphibians.
Your backyard salamanders hide in the dark, moist recesses of your woodpile during the day, and prowl within the woodpile and the surrounding area at night hunting for food.