### Instruction: What is TSA?
### Input: The Transportation Security Administration (TSA) is an agency of the United States Department of Homeland Security (DHS) that has authority over the security of transportation systems within, and connecting to the United States. It was created as a response to the September 11 attacks to improve airport security procedures and consolidate air travel security under a dedicated federal administrative law enforcement agency.
### Response: TSA stands for Transportation Security Administration in the United States. It is the agency that is responsible for the security of transportation systems within United States. They are mainly responsible for airport security.