Software can be distributed to the market in several different ways. The dominant form of distribution is the sale of commercial-off-the-shelf (COTS) software products on hard copy media (CD/DVD). Alternative distribution models that are becoming increasingly prevalent include shareware (usually intended for sale after a trial period), liteware (shareware with some capabilities disabled), freeware (free software but with copyright restrictions), public domain software (free with no restrictions), and open source software (where the source code is provided and users agree not to limit the distribution of improvements).
