License compatibility is the comparison of two or more licenses to determine if certain usages and actions can be made. Use this tag if the question would like to determine the compatibility of licenses, or their individual clauses.
Occasionally, software developers may want to combine code from different open sourced programs into one program. The only way for this to happen is for the two licenses to be compatible.
When a license is declared compatible, code licensed under these two licenses may be combined into a single program, given that none of the policies in the two licenses are disobeyed.
Compatible licenses have similar overall ideas (e.g. to make content available to everyone without charge), which make them compatible. If two licenses oppose each other, they cannot be compatible.