Open standards are a very nice thing to have. Open standards enable easy communication between different computers.
In 1969 some intelligent people decided to write down these open standards. They decided that all information necessary to support (read program) an open standard would be written down in a clear way (in plain text).
In 1981 they wrote an open standard for internet communication named IP (or Internet Protocol). This open standard enables all computers to connect to the internet.
In 1982 they wrote an open standard for using names on the internet (DNS or Domain Name System). Everybody uses the same open standard for names.
In 1982 they also wrote an open standard for sending e-mail. All computers can send and receive each others e-mail, because they all use the same open standard.
In 1984 they wrote an open standard to share and copy files between all computers on a local network. It enables all computers to share and copy files.
During the eighties, a lot of companies (Novell, IBM, Microsoft, DEC, ...) tried to impose their own undocumented systems for communication. They all failed, except one... Microsoft.
In 1987 Microsoft wrote an open standard describing their way of sharing and copying files.
Standards are a nice thing, since they enable everyone to communicate. Except for the 1987 Microsoft standard. People noticed, that the standard was incomplete, and they asked Microsoft about that. Microsoft never completed the standard.
So today, we have thousands of open standards that everyone can use, and we have near-monopoly-Microsoft refusing to co-operate with an open system that worked well for over thirty years.
All computers can communicate with each other in every way possible (names, internet, e-mail, www, sharing files, opening documents...). Only Microsoft keeps their standards secret.
Microsoft fooled the world more than once already...and they are at it again!
Help maintain real open standards (avoid the fake ones).