A text editor is used solely to write and edit text. You can copy, cut, paste, undo and redo. Text formatting is not available in those editors. Mostly text editors are used for programming purposes to write HTML, CSS, JavaScript, Php and other languages. An example of a text editor is sublime text or notepad++. Moreover usually in text editors you will keep on typing infinitely in the same line unless you click on enter to go to a new one.
A word processor allows you to edit text in addition to multiple other functionalities such as text formatting (italic, bold, underline, etc.). In addition to that word processors allow automatic spelling and grammar checks. It also comes with a thesaurus for word selections. Some word processors come equipped with predefined themes and templates to make it easier for you to start you work. Some popular word processors are Microsoft Word and Apple Pages.