'Though' and 'although' both mean 'in spite of' but...
When used as a conjunction, 'although' and 'though' are interchangeable. 'Although' is considered more formal.
Population growth is increasing, although/though some countries are creating restrictions.
When 'though' is used as an adverb, it is not interchangeable with 'although'.
This weekend, though, theaters were packed.
Hope that helps.