Technical Definition – A program that responds to HTTP requests. They differ from web servers in that they don’t usually talk to browsers, sending HTML that can be rendered into a user interface. Web services talk to other programs, sending data that can be interpreted by the machine that requested it.
Layman’s Definition – Web services are how separate systems share information within a network or over the internet.
How we use it – Sharing data between distinct systems is extremely important to streamlining workflows. Standing up new web services and making full use of existing ones in your current systems is how we accomplish complex integrations for our clients.