Can two computers connected to the same internet source view the same content?

If there is a computer upstairs on the internet, using a dial-up connection and a computer downstairs with the same dial-up connection, can one computer surf the internet and the other computer view the same content? The same question applies to broadband service.

In other words, the computer upstairs is on dial up. The line downstairs sounds like all that modem-popping, internet-surfing stuff. If I turn on the computer downstairs and plug in the phone line, can I view the same pages downstairs, download same songs downstairs,...etc while the computer upstairs is doing it? Without physically connecting the two computers or using routers or such. Just through the internet connection.

Can two computers connected to the same internet source view the same content?best antivirus software

If you've got some form on internet sharing set up, or two telephone lines then "yes".

Broadband is totally different as the broadband modem/router usually comes with multiple ports.

Can two computers connected to the same internet source view the same content?firewall

yep unless you specifically restricted content.
Yes
Yes. You can use a router. There are many available routers on the market today...

one of the most noticeable and most common router used today would be the "Linksys" type routers.