A software program designed for end users to accomplish specific tasks. Like specialized tools - a calculator app for math, a camera app for photos.
Netflix, Spotify, and your banking app are applications that help you watch videos, listen to music, and manage money.
“Application” is a general software concept, not a single cloud service. All major cloud providers host, run, and manage applications using compute (VMs/containers/serverless), storage, databases, and networking services.