Hello Akshayb.
It's easy to difference between equations and functions.
Equation: In an equation there's a unique value for each x, y...
Per example:
\[x + 3 = 2y\] and \[y - 1 = x\]In this given equation, values for x and y are uniques ( x = 1 and y = 2). You cannot change values because you won't get an equality...
(trying with x=0 and y=5)\[0 + 3 \neq 2\times5\]
Function: in a function, there are infinite values for x, y...
Per example: (s = speed, l = lenght in meters, t = time in seconds) Wich is my speed rate if i reach goal of 100m in 15 seconds?
\[s = \frac{ l }{ t }\] So... \[s = \frac{ 100 }{ 15 } = 6,7\] 6,7 meters per second is your speed (given values 100 for lenght and 15 for time).
And what if you reach it in 10 seconds, or 7 seconds or... 'x' seconds? As you can see, the value of 's' depends on the values of distance and time and you can change values all the time. That's a function.
I hope this post was useful ;)