Intrusion-detection systems (IDS) aim at de-tecting attacks against computer systems and networks or, in general, against information systems. Its basic aim is to protect the system against malwares and unauthorized access of a network or a system. Intrusion Detection is of two types Network-IDS and Host Based- IDS. This paper covers the scope of both the types and their result analysis along with their comparison as stated. OSSEC (HIDS) is a free, open source host-base intrusion detection system. It performs log analysis, integrity checking, Windows registry monitoring, rootkit detection, time-based alerting and active response. While Snort (NIDS) is a lightweight intrusion detection system that can log packets coming across your network and can alert the user regarding any attack. Both are efficient in their own distinct fields.