The semantic web is an idea of Tim Berners Lee to create a WWW of data rather than documents. Documents are made to be read by humans whereas the semantic web would be made to be read by machines and humans. I’ve found it hard to find a good high level description that doesn’t get too complex too quick but this works, for me at least
“The Semantic Web, Web 3.0, the Linked Data Web, the Web of Data…whatever you call it, the Semantic Web represents the next major evolution in connecting information. It enables data to be linked from a source to any other source and to be understood by computers so that they can perform increasingly sophisticated tasks on our behalf.”
@happybeing has been working on integrating SAFE with SOLID, a project built on semantic web protocols.