At least it was many years ago when I was there. In other words it 'includes" it's own suburbs, so to speak?
Correct me Houstonians.
But -- shshshsh, don't tell anybody. For some strange reason, Houston seems to stay off the national radar, and guess what? We like it that way. This place is big enough :)
Houston is a sprawled out city. It is covers 620 square miles of land. Twice the size of New York. Inside the loop is urban. Outside the loop is more suburban. The further away from the loop, more suburban. The loop leans Democratic. Outside the loop leans Republican.
The other way around really. Houston's size comes primarily from the city itself, not the outlying areas. Houston is the 4th largest city in the United States, and the largest city in Texas. However, what most people don't know is that the Houston GMA is smaller than the Dallas/Fort Worth GMA. 7 of the 10 largest cities in Texas are part of the DFW metroplex.