There are a number of differences between ants and termites. The body shape of an ant is like an hourglass--it narrows between the abdomen in the rear and the thorax in the front. The body of a termite is more cigar-shaped without the narrowing between the front and back halves of the body. When wings are present, ants have larger wings in the front and smaller wings in the back, whereas termite swarmers have relatively equal-sized wings. Ant wings are less veiny than termite wings.
Also, ant wings have a stigma (dark spot) on the leading edge of the front wing, and termite wings do not.
Ant antennae are bent or curved, while termite antennae are relatively straight. Also, termites eat the wood they tunnel through, causing damage to homes and property, while ants do not.