You might want to untrack certain files and folders when pushing code from the local system to the scratch Org. To do this, you have to create a file named forceignore. The sample format for forceignore is as follows:
# Specify a relative path to a directory from the project root helloWorld/main/default/classes # Specify a wildcard directory - any directory named “classes” is excluded **classes # Specify file extensions **.cls **.pdf # Specify a specific file helloWorld/main/default/HelloWorld.cls