Welcome to Execution Context in Javascript & Execution Stacks in advanced javascript in Hindi. In JavaScript, the execution context is an abstract concept that holds information about the environment within which the current code is being executed. Remember: the JavaScript engine creates the global execution context before it starts to execute any code. Execution stack, also known as “calling stack” is a stack with a LIFO (Last in, First out) structure, which is used to store all the execution context created during the code execution.