Execution Context

Execution Context (EC) is a record of information when code is executed.  

Two types of Execution Context

Global EC

• Created when a program executes
• Only ONE Execution context per program.

Function EC

• Created when Functions in programs execute
• Multiple Function Execution Contexts per program

Global Execution Context

Scope / Scope Chain

Scope determines the accessibility of variables and other values in a particular section of your code during runtime (it determines what your program has access to).