A question about download files

[CNwangbin]

First, wether the obo file equal to owl file?
Second, in obo file,there are some terms with "intersection of" tags.
I don't konw this meaning.
Could I see them as the equalent definition of GO:0000022?

[balhoff]

@CNwangbin the OBO file is intended to be equivalent to the OWL file, especially for the main release files at http://purl.obolibrary.org/obo/go.obo and http://purl.obolibrary.org/obo/go.owl. There are some features of OWL that are not representable in OBO files, but these features aren't generally found in the main GO file. You're correct, the intersection_of tags define an OWL equivalentClass expression. You can find a translation from OBO to OWL axioms here: https://owlcollab.github.io/oboformat/doc/obo-syntax.html