Map Components
Map files (having a .btm extension) store most of the components of a map. Items stored in the file include:
References to source and destination schemas
Links, including the link properties
Functoids with their properties such as input parameters
Other miscellaneous properties such as those associated with the grid and the map itself.
Although BizTalk Mapper compiles the map in the .btm file into an Extensible Stylesheet Transformations (XSLT) file, the XSLT is not part of the file. BizTalk Mapper produces the XSLT for the map only when you compile the project or when you validate the map. BizTalk Mapper packages the XSLT as part of the project assembly.