Pressed glass is glass that has been made by the process of hand or machine pressing (rather than "blowing" for example).
Depression glass is one type of pressed glass - it was made in the USA in the Depression era (circa 1930s) and was generally machine pressed on production lines. It is generally found in utilitarian shapes, such as luncheon sets, dinner sets, water sets and stemware - and in pale colors, such as light pink, green and blue. The moulded patterns tend to be light and in low relief. Typical manufacturers were companies such as Jeanette, Anchor Hocking and Federal.