This is a metaphor for a product, which states that it includes all the required parts for full usability. This may contrast to some products, which require for the full usability some extra parts to be bought separately - like batteries, but also things like ethernet network cable, or in some cases even the power cable. For software products it may mean that it provides some software parts for users' convenience, which usually may require extensions or plugins to be able to fulfill particular tasks (this concerns both the user programs and programming languages or libraries).