Checking in and committing are actions that save and update the changes made to a file or code in a version control system or repository. Checking in and committing can help track and synchronize the changes made by different users or developers working on the same file or code. The deployment script changes made by the first administrator were not checked in and committed is the most likely reason for the issue of the application load balancer being missing from the new deployment after a second administrator made some changes and ran the script. If the first administrator did not check in and commit the changes made to add an application load balancer to the script, then those changes would not be reflected or available in the latest version of the script used by the second administrator. References: CompTIA Cloud+ Certification Exam Objectives, page 13, section 2.5