The boundary line under the basket is known as the baseline.
Durand Line ,,
out of bounds
the back boundary line, and the long service line
The boundary where vegetation ends is called the timber line or tree line.I cannot find proof of this but I think it is simply called the 'TREE LINE' - sincere apologies if this is not correct.
The Himalayan Mountains is the natural boundary between China and India. China and India have fought battles over disputed parts of this boundary.
The line that seperates one air mass from another is called a boundary.
It is called a divergent plate boundary.