First Question:
The intersection of two lines is called a POINT. The diagram below shows where two lines |AB| and |CD| intersect:
Clearly, both lines meet at point x.
Second Question:
The intersection of two planes is a LINE.
A plane is a flat shape. The diagram below shows the intersection of two planes:
Third Question:
Through any TWO points, there is exactly one line.
When we have two points, we can only draw a single line to join them. Consider a line joining points E and F below:
It is only possible to get one line.