these lines are called intersecting lines
I assume you mean that the line goes through a certain point. There is no limit to how many lines you can have through the same point.
Elevation contour lines.
All the lines meet at one point: a single solution. All the lines are the same: infinitely many solutions. At least one of the lines does not pass through the point of intersection of the others: no solution.
An infinite number of lines can be drawn through a single point, but only one through two points (of course, if the points don't have the same coordinates).
Altitude (height above sea level)
Two or more lines containing the same point are intersecting.
One if the two lines meet, none otherwise. But skew lines do not lie in the same plane, by definition.
crossing Two or more lines passing through the same point.
No. Two lines can include the same point only if they intersect.