difference between OpenStreetMap and the OpenStreetMap wiki
OpenStreetMap is a project
aimed squarely at creating and providing free geographic data such as street maps to anyone who wants them. This is because most maps you might think of as free actually have legal or technical restrictions on their use, holding back people from all walks of life who would like to use a map for one reason or another.
has created a cool online editing interface that allows anyone to upload their GPS tracks and contribute to the map. The data created can then be used in lots of different ways for free - something that isn't possible with commercial mapping.