The KVM console is a video over IP representation of the blade server. This facility is required to build and manage the servers from remotely. In an order to access each blades remotely , a pool of IP addresses is assigned as a management
A good example is located in the link below;
While the cable managment arm is a physical device that you install on the hardware. I listed some pros and cons in my opinion over the Cable Managment arm.
GREATLY reduced likelihood of accidental disconnection when working on other things in the rack. This is big for me .. it just sucks when you are debugging a problem with server A and accidentally knock out the power cord for server B.
Tidiness / Cleanliness - the rack just looks better with arms, and it is harder to keep the rack tidy without arms.
No need to disconnect (and reconnect) when doing maintenance. Even if the maintenance is done offline, not having to touch the connections makes it easier.
Airflow / cooling - the arms can reduce airflow, particularly in dense racks.
Difficulty changing cables - I think this is overblown. When swapping a cable in a crisis you skip the cable management, get both ends plugged in, and make it pretty when things settle down.
More moving parts - can pinch fingers, catch on things, etc.
These two items are completely different.
The cable management arm is an extra part you order that attaches to the server on the backside to aid with cable management in a datacenter environment.
The KVM is a keyboard, video, and mouse combintation you need to access the server if you were physically standing next to it.
Let me know if you need clarification.
Posting it in case anyone else is also looking for the same:
UCSC-CMA-M4 - Reversible CMA for tool-less C240 M4 ball bearing rail kit