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Siam? Thai? Does it different? The answer is NO.

Siam is Thai and Thai is Siam.

However, these 2 words can describe on another way. If you want to visit Thailand tourist attractions Kanchanaburi, for instance, you can say Thai nuture in Kanchaburi is wonderful. Conversely, if you visit Bangkok; the capital, such as a couple royal temple you would say Siam temple is fantastic. 

So, SIAM might be called as 'culture' or 'traditional' ,whereas THAI might be called as modern siam tangible aspects.