Word processing software refers to computer applications that are specifically designed for creating, editing, formatting, and printing documents. These software programs provide various tools and features to make the process of creating and editing documents efficient and convenient. Among the given options, all of them are word processing software.

Detailed explanation:

1. WordPerfect:
WordPerfect is a word processing software developed by Corel Corporation. It is a popular choice for creating and editing documents due to its comprehensive features and compatibility with different file formats. WordPerfect offers tools for formatting text, inserting tables, creating graphics, and managing references. It also provides options for spell checking, grammar checking, and thesaurus.

2. Wordpad:
Wordpad is a basic word processing software that comes pre-installed with the Windows operating system. It offers essential features for creating and editing documents, such as text formatting, page layout options, and the ability to insert images and objects. While it may not have as many advanced features as other word processors, Wordpad is suitable for basic document creation and editing tasks.

3. MS Word:
MS Word, short for Microsoft Word, is a widely used word processing software developed by Microsoft. It is part of the Microsoft Office suite and provides a comprehensive range of features for creating, editing, and formatting documents. MS Word offers extensive formatting options, including font styles, paragraph formatting, and page layout customization. It also includes features like spell checking, grammar checking, thesaurus, mail merge, and track changes. MS Word supports various file formats and provides compatibility with other Microsoft Office applications.

Conclusion:
All the options mentioned in the question (WordPerfect, Wordpad, and MS Word) are word processing software. They are specifically designed to facilitate document creation and editing tasks. These software programs offer various features and tools to enhance the formatting, organization, and overall appearance of documents.