Answer
Number line is a horizontal or vertical straight line, on which points are mentioned after a regular interval of some units, ranging from negative numbers to positive number, left to right. An integer contains all the positive, negative numbers as well as zero but does not contain any decimal, rational, or in mixed form. A set of integers including positive, negative integers and 0 is written as, \[\left[ -1,-2,-3,-4,0,1,2,3,4 \right]\]
The difference between each integer is a single unit. The shift of a single unit number is done from left to right on addition of each unit positive number addition