Postage stamps are first issued on a specific date, often referred to as the First day of issue. A first day cover usually consists of an envelope, a postage stamp and a postmark with the date of the stamp’s first day of issue thereon.
There are two basic types of First Day Covers noted by collectors. The first and often most desirable type among advanced collectors is a cover sent through the mail in the course of everyday usage, without the intention of the envelope and stamp ever being retrieved and collected.
The second type of FDC is often referred to as "Philatelic," that is, an envelope and stamp sent by someone with the intention of retrieving and collecting the mailed item at a later time and place. The envelope used for this type of FDC often bears a printed design or cachet of its own in correspondence with the stamp’s subject and is usually printed well in advance of the first day of issue date. The latter type of FDC is usually far more common, and is usually inexpensive and relatively easy to acquire.