An intrusion prevention system is a computer security device that exercises access control to protect computers from exploitation. Intrusion prevention technology is considered by some to be an extension of intrusion detection (IDS) technology but it is actually another form of access control, like an application layer firewall.
An Intrusion Prevention system must also be a very good Intrusion Detection system to enable a low rate of false positives. Some IPS systems can also prevent yet to be discovered attacks, such as those caused by a Buffer overflow.

Security Information Management
Security Information Management (SIM) is the industry-specific term in computer security referring to the collection of data (typically log files; e.g. eventlogs) into a central repository for trend analysis. This is a basic introductory mandate in any computer security system. The terminology can easily be mistaken as a reference to the whole aspect of protecting one's infrastructure from any computer security breach. Due to historic reasons of terminology evolution; SIM refers to just the part of information security which consists of discovery of 'bad behavior' by using data collection techniques. The term commonly used to represent an entire security infrastructure that protects an environment is commonly called Information Security Management (InfoSec).