Word Processors create text documents. Simple "Formatted Documents" are the most common in this category, and incorporate features such as: Titles, Bold, Underline, Italics, Bullet Lists, Numbered Lists, etc. A "Table of Contents" for longer, more complicated documents can often be desired as well. There are a number of simple to use Office Suites today that can cover these basics, as well as offer higher functionality.
One thing to keep in mind however, is that the more features that are offered in a software program, the more complicated it can be to use.
Keep in mind that you can "copy and paste" into any e-mail "client" (such as: G-Mail, Yahoo! Mail, Hotmail, etc.) from any other word processor source such as: Google Drive, Open Office, MS Office, etc. In the near future however, most of this sort of thing will eventually be done through systems such as Google Drive "Sharing" and collaboration.
Remember too that there really is no "conversion" necessary with Copy-Paste. There may be some unexpected formatting results, but in terms of saving time, a simple "Copy-Paste" task will usually get the job done.
Here is a look at a few simple Word Processors:
E-Mail Clients
E-Mail Clients are the programs that are used to send and receive e-mail. Many of these clients today offer very rich formatting options for composing messages. These programs can be very useful for creating quick and simple "documents".
Google Drive
Originally known as Google Documents, Google Drive is a "Cloud Based" (on-line) system of creating and managing documents. The most powerful feature of this system is the ability to "Share and Collaborate On" documents with groups of people.
"G-Drive" offers a very simple interface on the surface, but also has deeper functionality for those folks who want to dive into that.
As well as creating documents in the G-Drive system, you can also upload documents of any type into the system, and share those as well. (Such as PDF's, Images, etc.)
"Sharing" has a number of options. The "Owner" can decide if shared documents can only be Viewed, with additional options to allow viewers to either Comment on, or Edit the files/documents. This is an extremely powerful tool for group collaboration on documents. Shared access can be set to varying degrees of Public to Private.
Open Office
(Apache) Open Office is an "Open Source" (i.e. "free software") project that is competitive to MS Office. It is highly recommended. Get the Download at OpenOffice.org.
It is always suggested to use something like Google Drive first. What you cannot get done there, then try Open Office.
Products like Microsoft Office (including Microsoft Word) are great... but they are also expensive. Plus they are migrating to a "Subscription and Cloud-Based System" of software management (MS Office 365). The real question in the end is this however: Who do you want to feed?
Cross-Platform Functionality
The biggest issue by far is this:
Being able to easily share what you create is a very important function. A common method of the past was to create and save a file using a word processor, then attach it to an e-mail. Problems can occur with this process however, especially if the recipient of the attachment does not have the same software that you do. There are many ways to translate and/or read various popular file formats (such as MS Office), but too often things (especially "Formatting") can get lost in the translation.
In all cases, it is always best to stay as close as possible to having everyone working in the same realm of software.
Fortunately the Internet, particularly the World Wide Web, allows easy "Cross Platform Functionality". With the primary Platform to overcome being the Operating System (Windows, Mac, Linux, Android, etc.), which is closely followed by the actual Software Program itself (word processor, spreadsheet, etc.).
Open Office is "free", and is available for the "Big Three" (Windows, Mac, and Linux).
Linux is an operating system compatible with all "IBM Clone" type PC's (that typically run MS Windows)... and is another "free" open-source project.
The real power however is in the Web... and Cloud Based Computing.
Browser Software
The "Web Browser" is the key to it all.
A Browser allows you to view information that is stored on web servers. In the simplest terms, it allows you to view and interact with websites and web pages... like the one you are reading now.
Browser's, and the Web in general, have become very sophisticated since the Web first came on-line, around 1990.
In general, all browsers are the same... but there are differences.
Keep in mind that you can load and run more than one browser at a time on your system (providing that you have the hardware resources to do so).
:-)