OK here's some info on US credit cards:
store cards - department stores issue credit cards. finance charges are generally high, about 21% APR. of course, these cards can only be used at their own outlets.
cards from financial institutions. majority issue both master card and visa (just a matter of preference). there's also discover and american express. car manufacturers, airline companies, and other major commercial companies also issue visa/master card.
regular visa/mc - credit limit from 0 to about $3000. i say zero because some require you to make a deposit and then that amount serves as your limit. limits can go higher the longer you remain as a customer and have a history of responsible use. finance charge around 18 - 21%
gold visa/mc - credit limit generally at $5000 but again depending on history with the provider, can be up to $7500. finance charge is a little less at between 15 - 18%, sometimes lower
platinum mc/visa - generally offered limit is $10000. again depending on user's credit rating and ability to pay, limit may be higher and sometimes unlimited. fixed finance charges between 7 - 12%. also, "teaser" rates of 0% are normally offered for between 4 - 18 months, then fixed at 7 - 12%
titanium mc/visa - seen these offered for about 5 years. they are still rare. same rates as platinum cards.
for all the cards, there is normally a 20 -25 day grace period; therefore, if you pay the balance in full on or before the due date, there is no finance charge incurred.
on the other hand, cash advances normally incur finance charges right away.