What are your thoughts on data interoperability? I have a few contact lists (names, emails, numbers, addresses across a few services) that I'd like to consolida

What are your thoughts on data interoperability? I have a few contact lists (names, emails, numbers, addresses across a few services) that I'd like to consolidate into a single list and take that into whatever app I end up using. Is this at all possible? Have you come across any useful standards?