Also called Keystroke logger.It is hardware device or small program that monitors each keystroke a user types on a specific computer’s keyboard.Two types of keyloggers-
1.software based keyloggers
2.hardware based keyloggers
DOS and DDOS attacks
Denial of service or distributed DOS attack is an attempt to make a machine or network resource unavailable to its intended user.It generally consists of efforts to temporarily or indefinitely interrupt or suspend services of a host connected to the Internet.
DDOS attacks are sent by two or more persons or bots.DOS attacks are sent by one person or system. Perpetrators of DOS attacks typically target sites or services hosted on high profile web servers such as banks,credit card payment gateways and even root nameservers.example-SYN flooding