Ah yeah software licenses ... sometimes it's hard to understand exactly what can and can not be done
and so here this site which explains Software Licenses in Plain English
and wait for it ... not it's not only open source licenses, it's all kind of licenses
here an open source example with Apache License 2.0
and another example with the Youtube TOS (Terms of Service)
Wether you want to apply a license to your own software sources or want to use other services and API in your own commercial software, it is always good to know and understand the limitations and most importantly the real meaning of those often verbose texts.