Just watched this vid and they are so similar.

Historically much of Thailand belong to Cambodia. Draw a line south of Petchaburi and leave out Lanna and you get the Khmer provinces of today's Thailand. Once you start visiting the old temples, you will see that almost all were Cambodian. These which were not are called in THailand Djavarati because the Thais dont like to acknowledge the mon culture. So Djavarati = Mon.

The first Thai immigrants were not much more than mercenaries or small war lords on the borders to Lanna, serving the ruler in Angkor.

When the Cambodian empire crumbled, Thais took over most of it . THey also appreciated the superior culture to an extent that they simply kidnapped the royal ballet and other useful institutions. The royal language is a derivative of the Cambodian court culture. So in terms of the old state structure and court rituals you look at a copy cat or even less than that.

Popular culture is of course very similar. Bother countries lived on rice and fall of a state did not mean the disappearance of the people living in it. Thailand was called Siam until some generals who ruled the country in the 1930 and 40s got some inspiration from places like Germany and declared that this was now the country of the Thais. Not very funny for the Laotians, Lanna, Muslims, Khmers, you name it. They became second class if at all, some are still denied their citizenship. Dirty habits die slow in Thailand.

If you draw a map of Thailand with its deported populations from the South and North you will get a rather mixed result. Cambodia is not different. It has relatively more Vietnamese than Thailand and the Muslims are called Cham and form a different group than the various Muslim communities in Thailand. Cambodia and Thai integral nationalists hate each other for obvious reasons but are made of the same sick idiology.

So forget a little about those borders, they were made by French, British and Thai colonial administrators (yes, the Thais were not any better) and did not care about the people much less than asking them.

Cambodia is much poorer being a victim of the US unlike Thailand which was a partner in the crime. Thailand gad even deals both with China and the US supporting Pol Pot after the liberation of Cambodia from the genocidal regime.

Differences? Bad healthcare and infrastructure in Cambodia but you can eat almost anything without burning your butt off. Tons of good Vietnamese food, and the people are not as much infected by such diffuse and xenophobic concepts of 'Thainess.'