Enterprise Manager Grid Control 11gR1

Enterprise Manager Grid Control is a system management software that delivers centralized monitoring, administration, and life cycle management functionality for the complete IT infrastructure, including systems running Oracle and non-Oracle technologies.
Enterprise Manager Grid Control Architecture
- Oracle Management Agent (Management Agent)
- Oracle Management Service (OMS)
- Oracle Management Repository (Management Repository)
- Enterprise Manager Grid Control Console

How to Install Grid Control 11g? We can review on OEM document -> Oracle® Enterprise Manager Grid Control Basic Installation Guide and Step by step Installation of 11.1 Grid control [ID 1059516.1] (oracle support).
Install Grid Control 11g (my test):
1. Install WLS 10.3.2
2. Install Oracle Database(Enterprise Edition) and Create Database (ID 412431.1)
3. Install Grid control 11g

$ emctl status oms
Oracle Enterprise Manager 11g Release 1 Grid Control
Copyright (c) 1996, 2010 Oracle Corporation. All rights reserved.
WebTier is Up
Oracle Management Server is Up

After Installed, We should be able to access webs.
- WebLogic Server Administrator Console https://hostname:7101/console/

- OEM Grid Control https://hostname:7799/em/

However we can review Features.
Reference:
OEM 11gR1 Documentation
OEM Downloads
Oracle Database 11gR2
Oracle WebLogic Server