Port Scanning: The act of systematically scanning a computer's ports. Since a port is a place where information goes into and out of a computer, port scanning identifies open doors to a computer. Port scanning has legitimate uses in managing networks, but port scanning also can be malicious in nature if someone is looking for a weakened access point to break into your computer.

Port Scanner: A port scanner is a software tool used to get the details about all ports of a system. These ports are used to deliver specific services to several users; in short we can say that the services are grouped to ports. You can't directly access the services in a network or a system unless and until the services are defined with specific port numbers. Hackers have various tools to scan the ports of a server or system and get the details about commonly used ports, ports which default services etc. Later, the hacker can penetrate his malicious code to steal information as well as to break down your system.

IP Spoofing: IP spoofing is the making of IP(Internet Protocol) packets to hide the identity of the sender by impersonating other systems. It is also known as address forgery and is a hijacking technique in which the attacker impersonated as a trusted host to hijack websites or gain access to a network. The attacker obtains the IP address of another host and alters the packet details or headers so that this host appears to be the source.