@Russell *******
The concepts are related. If you want a business you need a business visa. If you want to live here, without the ability to work, then you have many other visa options to choose from. LTR, DTV, Retiree, Elite, ED, Tourist.
Which is "best" for you depends on many individual circumstances including things like your age and economic situation. The "best" visa to live in Thailand without working, without respect for cost, is the Elite visa. That'll cost you like $20,000 USD for a 5 year visa. If you are over 50 then the retiree visa is best, assuming you can put the 800k THB into a Thai bank account. Most likely you'll simply need to come in on a tourist visa, stay for a couple of months, and then go elsewhere.