Source code editors have features specifically designed to simplify and speed up input of source code, such as syntax highlighting, autocomplete and bracket matching functionality. These editors also provide a convenient way to run a compiler, interpreter, debugger, or other program relevant for software development process. So, while many text editors can be used to edit source code, if they don't enhance, automate or ease the editing of code, they are not "source code editors," but simply "text editors that can also be used to edit source code."
A few source code editors do syntax checking while the programmer types, immediately warning of syntax problems. A few source code editors compress source code, typically converting common keywords into single-byte tokens, removing unnecessary whitespace, and converting numbers to a binary form. Such tokenizing editors later uncompress the source code when viewing it, prettyprinting it with consistent capitalization and spacing. A few source code editors do both.