Here in Tennessee, and much of the south and southeast US, there are a number of regular visitors to a city or suburban bird feeder. A wider range of species can be found in rural areas. Here are the main four types of birds seen at my backyard feeder in the winter.
The chickadee: Both this and the next little bird are in the Paridae family. The black-capped and the Carolina chickadee look much alike, though the Carolina variety is somewhat smaller. The black cap has a larger area of white on its breast and is noted for its call of "dee-dee-dee"!
The tufted titmouse: This little bird has a tiny tuft of feathers on its head. It is often called mouse-colored and if you've ever seen a common house mouse, you'll agree. It also has little round black eyes like a mouse. Just under its wings, you'll see a blush of color, a pale rust.
Both the above birds have a wide range from southern Canada to the Gulf states. They like woodlands, so can be seen in rural areas as well as suburbia where they find shade trees and thickets for homes.
The cardinal: The main specie of cardinal in my area is the Northern Cardinal, or cardinalis cardinalis. The male is all red with a pointed crest and a black mask over his eyes and below his large orange beak. The female is often called "buff-brown", but seems to me she almost has a greenish tinge to her. She also has a black mask, some red on her crest and wings and a large orange beak. The northern cardinal can be seen from southern Ontario to the Gulf states and love the bushy edges of suburban gardens.
The house finch: The male of this specie looks like someone dipped it in pink or orangish-pink ink. It is often mistaken for the purple finch, which is a much larger bird with a larger bill. The females have no color and some mistake them for sparrows. To identify them, look for dark stripes on the sides and belly of these little birds. They are somewhat newcomers to our area -- introduced to the northeast US around 1940. Their largest range is from the western US into southern Mexico.
Of course I have other kinds of birds show up in my backyard as well, but these four can be most regularly seen out my windows.