Benefits of subnetting:

What are the benefits of sub-networking? There are three primary reasons:

1) Organization – With subnetting, you can organize resources into smaller networks and logically group assets together for better organization.

2) Security – Putting different resources on different networks allows you to be able to granularly restrict control between assets, either through the use of router access control lists or a network firewall.

3) Network efficiency – Using subnets decreases the size of the broadcast domains. This means that as there are less hosts on a subnet and an overall less chatty network.