A word processor is a software program for creating and editing rich text documents. Word processors include more features than simple text editors, offering users the ability to customize fonts, text styles, and page layouts. They often include proofreading features like spell check and grammar checks.
Word processors typically include toolbars and panels that provide advanced editing capabilities. Examples include line and paragraph spacing, text alignment, list formatting, and indentation margins. Some word processing applications allow you to create text styles, such as titles and subtitles, which you can to apply to text throughout a document. For example, you can create a "Header 1" style for section headers. If you change the style, it will update all the section headers in the document.
Page layout controls allow you to adjust the overall structure of a document and how it will look when printed. For instance, you can adjust the size of the page margins to increase or decrease the space between the text and the edge of the page. You can also add headers and footers that appear in the top or bottom margins of every page. Many apps allow you to insert automatic page numbers as well.
A word processor is one of the core components of an "office suite," along with a spreadsheet application and presentation software. Some office suites include several other applications as well. Examples include Microsoft Word, Apple Pages, OpenOffice Writer, and Google Docs.