Question

what is independent variable

Answer 1

first of all a variable is what?
a variable is pretty much just a value that has the ability to 'vary'
second of all a independent variable is the variable which can be modified.

Answer 2

think of a graph (x,y, nothing fancy). x is the independent variable. y is what u r interested in (in a standard plot). let us say heart rate or blood pressure (dependent) per time of the day (independent - it is not for u to change).
cancer rate (dependent) per age (independent). etc

Answer 3

The factor you can control
(like the temperature, how much of a drug each person takes, etc)