Identification

• A file with the .js file extension is known either as a Javascript file or a Jscript executable file.
  
  

Function

• Both types of .js files contain a list of instructions that computers follow to complete tasks, however each file is written in its own programming language. The .js file extension serves as a marker to allow computers to recognize that the file holds these instructions.
  
  

Languages

• Javascript files are written in the Javascript programming language developed by Sun Microsystems. Jscript executable files are written in Jscript, which is a version of Javascript created by Microsoft.
  
  

Uses

• Both types of .js files are typically used to create features on Internet websites, such as opening drop-down boxes or launching pop-up adds.
  
  

Considerations

• Because both types of these files are necessary for websites to function properly, never delete a .js file from your computer.