I have discovered the menu at upper left in Gmail (Google mail). Among the features there are 'Documents' and 'Calendar'. Documents includes slightly truncated versions of MS Excel, MS Word, and MS their presentation software. The Excel and Word clones contain more or less all the features anyone not working full-time in those applications would ever want. I don't know about the presentation software and don't care.
There are several large advantages the Google version of Office has over the Microsoft version. One is that it is free. MS Office costs $400. Another is that it is online. When your disk crashes, your computer is stolen or lost, or just not where you are, your spreadsheets and Word documents are still readily accessible. They are also password-protected if that matters to you. They are also shareable with anyone with a free Gmail account whom the user specifies. They can be shared as read-only, or shared with permission to edit or delete. The Google word processor also includes the comment feature. In theory one can do all these things with MS Office over a LAN, but in practice security and permissions makes it so cumbersome it never happens. Over the internet it is easy and global.
There is also a Calendar application which does much of what MS Outlook does, but in a better, more relational-database kind of way. I was confused at first that there seemed no way to code different appointments with different colors. I have since figured out that one creates additional calendars, each with its own color, and assigns each appointment to one of the calendars. One clicks the clickbox next to the calendar and it is displayed. Click several and several are displayed. Other calendars like national and Jewish holidays and phases of the moon are provided as well, as in Outlook. As with the other documents, calendars can be made viewable and or editable by specified Gmail users. In theory these sharings are for coworkers or supervisors and underlings. I think the calendar would work best for wives and husbands.
A feature that is not provided in Outlook is the weather calendar. Since at some point or another I must have entered my location, it shows the weather forecast for the next three days as icons of rain or sun. While it is easy to see how they do it, it is still way slick.
There is a bunch of other stuff as well, including 'maps' which is like Mapquest but faster and higher resolution.
Gmail is free but is available only by invitation from a Gmail account holder. One is permitted 50 invitations and the number renews every so often. I think this prevents it from being used as a way to publish spam.
If anybody is interested, write me at firstname.lastname@example.org and I will invite you.