Software Versioning is a practice of assigning unique numbers to software released.There are many different software versioning techniques(like semantic versioning,date of release,unary Numbering) but we will be covering semantic versioning which is a denoted as follows:
x.x.x->1.2.3
Where x denotes a number.
Here we have three numbers and these three numbers have special meaning.Starting from extreme right the first number is called patch version.Patch version is changed when a bug is fixed in a software.The middle number is called minor version and is changed when there is a new feature which is backward compatible(meaning you can update the software without worrying about compatibilty issues).The number on extreme left is called major version and it shows that the software has undergone major update and it is not backward compatible(meaning it is not safe to update to this version)