I hate to be picky - but as far as I am aware there isn't a one year visa!
You can have a single entry non immigrant visa valid for 90 days and then thats it finished, or you can have a multi-entry non-immigrant visa, again valid for 90 days upon which time you can leave the country and re-enter and you will receive a further 90 days. You can do this proceedure every 90 days until the visa validity expires (one year). If you are smart you will do the final re-entry just before the visa expires and then can strtch the one year validity to almost 15 months.
Either the single entry or multi entry non immigrant visa can be extended after a minimum stay here of 60 days at an immigration office in Thailand, provided you meet the criteria for the category you wish to claim and if successful in your application - the visa will receive an
extension of up to one year.(But you must report to an immigration office every 90 days to verify your address)
In the first year this will begin from when you first entered Thailand, so will expire on the anniversary of your arrival in the kingdom. Second and subsequent applications will be valid for one year from the date of application.
A visa is obtained outside the country, and allows you to enter a country, and you will then be given a permit to stay stamp for a nominated number of days depending on the kind of visa held.
An extension is granted inside the country.
To the best of my knowlege (ha ha disclaimer LOL)
Paul
