A TiddlySpace space comprises of two collections of tiddlers: a Public bag and a Private bag. Tiddlers in the Public bag are visible anyone who has access to the TiddlySpace server, in the case of http://tiddlyspace.com that is anyone on the Web. Only a member of the space may alter a public tiddler, though this is default Access Control may be changed by a member of a space using the TiddlyWeb HTTP API.