You can execute programs, upload, download, run backups, and most other things. Many ISP's lockout any commands that may cause them or their customers harm, to prevent accidental problems. NT hosts probably will not allow Telnet connections. Traffic - The volume of data transferred at any given web site. Bringing one page up on your browser might count as a large number of hits.
Traffic also refers to the amount of data transfers occurring on a server.
The formula is the total amount of data per page times the number of times read. Web Host - The company that owns the machines. They provide a place for your site on their computers and you use their bandwidth. The Host makes those machines available to the internet. Whois - An internet finder program.