A web service is a software system designed to support communication between machines over a network. In the Internet, these services are increasingly popular and, essentially make the functionality of a software system accessible through an interface or API.
A mash-up is a combination of information or functionality from two or more sources, normally open APIs, that that let you create a new web service. At Tyven we use them to combine sources of information or additional functionality and generate a new service with added value for our customers.
A widget is a mini-application that serves as a window to access dynamic content provided by external services to the platform in which it resides. Because of its ease of installation and simplicity, it is the ideal way to provide a large number of users with personalized access to web information or functionality from any device connected to the Internet.