What are the advantages and the disadvantages between Colocation & Dedicated hosting in your opinion.which you like better and which to choose?
The difference in that a dedi is served by the host unlike the colo. And host pays the the employees of the datacenter for its serving (in case of breaking something). If something has broken in the colo you have to go to the datacenter and repair it yourself.
You choose colocation if you would like to have more flexibility in managing your server not only in terms of software but even in hardware. This is applicable if you would like to upgrade or attach peripherals to your server.
With colocation, you do own your hardware, but remember... that also means you will be responsible for any failures. If you rent a dedicated server, your provider will take care of any costs for you.
Colocation means you provide your own server and can configure it any way you want, but ultimately makes you responsible for your hardware and any failures. Also unless you pay for management you need to know how to run your own server and do things like backups and configurations of OS and things like that.
Usually you are better off with a Dedicated Server or VPS unless you have vast experience and can manage your own server and it's hardware.
Dedicated is renting a server, where the host provides all the hardware, connections to the net, and so on. Colo means you go out and buy a server and pay the colo provider to lease space in a rack in their data center, and hook your box up to the net.