Theory:

Consider the game of balloon shooting. The balloons are ordered as provided in the image given below.
 
shutterstock_131022419.jpg
 
Imagine Ram's best friend challenges him to shoot the blue balloon. As there are many blue balloons, Ram asks his friend as to which one.
 
If you were Ram's friend, how would you describe the blue balloon's position to be shot?
We could describe the location as the \(3^{rd}\) balloon to the right on the third row from the top.
 
Like how we used numbers to represent the blue balloon's position, we can also represent a point using a graph sheet.
Location of a point
Let us look at a point on the graph sheet and discuss how it is located.
 
Figure 6.svg
 
The point \(A\) is located \(4\) units from the \(x\)-axis and \(3\) units from the \(y\)-axis. Here, \((4\), \(3)\) is also known as \(x\) and \(y\) coordinates.
 
Coordinates: Coordinates are used to locate the position of a point on the graph easily. They are expressed as \(x\) coordinates and \(y\) coordinates.
 
\(x\) coordinate \(=\) Distance of the point from the \(y\)-axis
 
\(y\) coordinate \(=\) Distance of the point from the \(x\)-axis
  
While expressing co-ordinates of a point, the \(x\) coordinate is always written first, followed by the \(y\) coordinate.
Linear graph
When a straight line could join the graph's points, then it is a linear graph.
 
Figure 7.svg
 
Here, we can join the points \(A\), \(B\), \(C\), and \(D\) to form a straight line. Hence, the points form a linear graph.
 
In other words, in a line graph, the points are joined using bits of line segments. A line graph does not form a straight line. Whereas in a linear graph, the points on the graph join to form a straight line.