It deploys applications into cloud environments is incorrect. The Continuous Delivery (CD) pipeline deploys applications.
It runs at night and generates a nightly build from the files in the version control system is incorrect. The 'C' in CI means the pipeline runs immediately when new files are pushed or merged into the version control system.
It builds applications continuously from the files in the version control system is correct
It builds cloud infratructure (CI) from infrastructure-as-code files is incorrect. CI stands for Continuous Integration, not Cloud Infrastructure.