Anti-malware tools are tools that attempt to prevent, detect, and remove, all types of malware.
In the past tools have differentiated between classes of malware such as viruses and spyware. You would need a separate utility for each: one anti-virus program, and another anti-spyware.
Viruses and spyware and other forms of malicious software are all taking on each others characteristics to the point where the distinction between them is not only difficult to characterize, but ultimately not useful. They’re all bad.
Hence the term malware, to refer to all forms of malicious software, and the migration of security software targeted at a particular class of threat in to more all-encompassing anti-malware tools.
Antivirus software was originally developed to detect and remove computer viruses, hence the name. However, with the proliferation of other kinds of malware, antivirus software started to provide protection from other computer threats. In particular, modern antivirus software can protect users from: malicious browser helper objects (BHOs), browser hijackers, ransomware, keyloggers, backdoors, rootkits, trojan horses, worms, malicious LSPs, dialers, fraudtools, adware and spyware. Some products also include protection from other computer threats, such as infected and malicious URLs, spam, scam and phishing attacks, online identity (privacy), online banking attacks, social engineering techniques, advanced persistent threat (APT) and botnet DDoS attacks.