Tracfone uses both GSM phones and CDMA phones. Depends on where you live or where you activate phone - the physical address. Yes, Tracfone does not own any towers - Tracfone rents "space" from most of the major cell companies.
Tracfone web site is the best for deals on new and refurbished Tracfones. Refurbished phones are often better than new phones. Certainly there are sales at Kh*ls, Wally Mart, etc.
Always get a phone that has double minutes for live. Always go online and looks for current 'coupon' codes - for free added minutes when you do add a minute card. Coupon codes are always listed online someplace - do a search. You will find many and always write down at least 2 as some have expired. But Tracfone is always adding new coupon codes.
To find out who your home carrier is look here:
LINK
Tracfone is not and never has been the least expensive way for cell phones. But for those who don't make many calls and do not want any contract - it is the best. Net10 and Straight Talk - are both owned by Tracfone. Straight Talk has unlimited talking plans that can be good for those that talk - all the time.
Tracfone is a company from South America. Tracfone Customer Service can be a challenge for some - as the CS agents - English is not their primary language. But if you do have to call CS - be patient and leave yourself plenty of waiting time.