In Ops Center, asset discovery is a process in which the software determines what assets exist in your environment. You can't monitor an asset, or do anything to it through Ops Center, until it's discovered. I've seen a couple of questions about how to discover various types of asset, so I thought I'd explain the discovery methods and what they each do.
Find Assets - This discovery method searches for service tags on all known networks. Service tags are small files on some hardware and operating systems that provide basic identification info. Once a service tag has been found, you provide credentials to manage the asset. This method can discover assets quickly, but only if the target assets have service tags.
Add Assets with discovery profile - This method lets you specify targets by providing IP addresses, IP ranges, or hostnames, as well as the credentials needed to connect to and manage these assets. You can create discovery profiles for any type of asset.
Declare asset - This method lets you specify the details of a server, with or without a configured service processor. You can then use Ops Center to install a new operating system or configure the SP. This method works well for new hardware.
These methods are all discussed in more detail in the Asset Management chapter of the Feature Reference guide.