These control where your email goes. Be very careful with these, if you get this wrong you will lose email. You can’t point these at just any server, you have to have agreed this with the ISP that controls them. The ‘priority’ field in the MX records governs the order in which mail servers are [...]

You will now be able to buy the right to sell or create your own domain extensions including .poker for example.  No doubt companies will go after extensions related to their own brand like .ebay for example.  I suspect some will try to make cash by paying $39,000 or more for company names and do [...]

CNAME records are domain name aliases.  On the Internet, machines will often have multiple functions such as web-server, ftp-server, chat-server etc.  CNAME-records can be used to give a single computer multiple aliases to mask this.
For example machine “www.machine.com” may be both a web-server and an ftp-server, so the two CNAME-records are defined as www.machine.com = [...]