Javascript is a programming language JQuery is a javascript library which has a very high adoption rate amongst web developers using javascript

Javascript is a client side browser compatible scripting language. JQuery is a Javascript library with its own prototypes,actions,sub routines,functions.

Like how .net framework made of classes and methods , Jquery is also one type of framework made of javascript.

jQuery is Library of Java Script and in .NET you can easily add the Java Script file but to add the jQuery you had to firstly install it as it's a "Nuget Package"

j query is an an library of java script