The word malware is mingling of two words namely "malicious" and "software". Malware is a general term used to describe a number of malicious kinds of software. This includes spyware, adware, trojans, viruses and much more. Spyware on the other hand is a specific term related to malware but it is different to other malicious software as it is designed to perform a different function. Most PC users consider these terms to be the same thing basically. Although they all harm our computer, they are not exactly the same. All these malicious software behave differently.
Malware is a general term used to describe all kinds of hostile and intrusive program codes that include the ones mentioned above. It includes anything that is aimed at performing malicious functions on your computer. The meaning of these terms such as spyware, viruses, trojans, worms etc has changed over a period of time. Malware is a term used for referring to how malware infects your system while others are used while the other terms describe what a malware does when it is active inside your pc. Once malware becomes active inside your pc, it does many things. Sometimes it will try to replicate itself providing no harm to anyone and at other times it will be very nasty indeed:
This is not a malware really and it is software that makes use of some kind of advertising delivery system. Many times the way the advertisements are delivered is deceptive in the sense that they will reveal more info about you than you want to. On most occasions you will agree to the adware tracking, once you install the software it will come with. Most of the time, adware can be removed by uninstalling the software it was attached to.
Spyware is software which will monitor your pc and will reveal collective critical info to an interested party. This activity can be termed as benign when it is just tracking the web pages you are visiting. On the other hand it can be unbelievably invasive and will monitor everything you are doing with your keyword and mouse.
Ransomware alerts your computer system in a manner that prevents you from entering it normally. It will ask for a payment to get the computer unlocked.
Scareware appears to be something legitimate but when it is run, it will tell that the system is infected or broken in some manner. The error message is aimed at frightening you into doing something untoward.