REST – REST is a software architecture specification. It is a design on using HTTP URLs to retrieve and set information on the system. Rest is a webservice the accepts an HTTP URL string, with specifications on how to parse this URL and converts it to an execution.
JERSEY – This is a Java implementation of the REST architecture. Although there are several implementations, ( you can even create your own ), Jersey is the most widely used and it is based on the javax.ws.* libraries. The Jersey implementation is under the Glassfish software therefore its libraries are using org.glassfish.jersey.*
See Oracle’s Introduction of Jersey:
The Jersey 2.10.1 API documentation: