Swimmers can choose from a selection of different styles of swimsuits specially designed for training and competition. Men's training and competition suits are largely one of two types, briefs or jammers (shorts). Women's training suits can be one- or two-piece, but competition suits, generally speaking, are one-piece. Styles for women vary in cut and length.
Some athletes wear drag suits in training and practices. Drag suits are looser-fitting than regular suits, either from a lot of wear or due to specific design, and are meant to force the swimmer to work harder to move through the water given the increased drag. The general idea behind this practice is that, when the drag suit is removed, the swimmer will have adapted to increased drag and will, therefore, be able to swim faster without it.
Technical suits, often used in high-level competition, are specially designed with water-repellent fabric to reduce drag. These types of competition suits have been redesigned in recent years after they were found to give swimmers an unfair advantage - they were formerly made in a way that increased buoyancy. Overall, their fabric and compression abilities give competitors a slimmer profile in the water. Because the suits can cost hundreds of dollars and are also not made to wear for more than a few swims, they're generally reserved for elite competitions.