Subnetting is the process of subdividing a given network address to smaller sub networks. In order to create sub networks, we borrow bits from the host portion of a given network address.https://ippacket.com.au/lesson/subnetting/

https://ippacket.com.au/lesson/subnetting/

Subnetting is the process of subdividing a given network address to smaller sub networks. In order to create sub networks, we borrow bits from the host portion of a given network address.This helps us preserve network addresses and to be efficient in...

This would give you an idea about subnetting. https://ippacket.com.au/lesson/subnetting/

Procedure for Upgrading Cisco Catalyst 2960 Switch IOS http://ippacket.com.au/procedure-for-upgrading-cisco-catalyst-2960-switch-ios/