What Application is

Used interchangeably with program and software, this is a general term for a program that performs specific tasks, such as word processing, database management, e-mail sending or retrieval, or Web browsing. Unlike system software, which maintains and organizes the computer system (such as the operating system), an app is an end-user program.

The meaning of Code or coding

The act of creating computer programs, Web sites, and other applications. "Code" refers to the typed program instructions that programmers write. The written code is interpreted into a language that a system can read and execute. A favorite term among Web developers, code is often mentioned with interesting verbs. For example, you may hear programmers say, "We're busy slinging code," which means they are writing a computer program or programming a database or Web site.