Everything on a computer you can touch. You keyboard, mouse, and monitor, but also your hard drive, CPU and power cord.
Everything on a computer you cannot touch. Programs running on the computer, including your operating system.
Specialized software to work with or control one or several pieces of hardware, usually providing interfaces for high-level software.
Software provided for free or as a bonus on a magazine enclosed CD, encouraging users to share copies with friends and relatives. It might include advertisements and there is usually a more feature rich paid version.
Shareware that frequently reminds the user to upgrade to a paid version is called Nagware.
Shareware containing generous amounts of advertising to support its creators is called Adware.
Shareware that comes with a full featureset but encourages the user to make a donation to its developers is called Donationware.
Shareware that comes with a full featureset but encourages the user to make a donation to charity is called Careware.
Shareware that comes with a full featureset but encourages the user to send the developers a (picture) postcard is called Postcardware.
A stripped down version of the software to merely demonstrate the full versions capabilities.
Extreme cases of Demoware are called Crippleware and demos limited by a trial duration are called Trialware.
Fully featured proprietary software (i.e. no source code is publically available) that is offered free of charge.
Several similar and hastily produced pieces of software, usually from the same developers, focussing on product quantity rather than quality. Many mobile games for Android and iOS fall under this category.
Software that is announced and advertised but never officially released or cancelled, sometimes fishing for preorders.
Software that was released but then abandoned by its developers. It stopped receiving (often desperately needed) updates.
A kind of software created with malicious intent. Malware usually seeks to disrupt the users workflow in various ways. Viruses, trojans, worms, and all sorts of unwanted software could be classified as Malware.
A specialized kind of malware aiming to scare the user into performing a certain kind of action, for example paying for some dubious service, without actually causing any lasting damage.
A specialized kind of malware that encrypts your personal files to then demand a ransom to be paid for decryption.
Alternatively a specialized kind of malware that threatens to publish private and/or intimate files unless a ransom is paid.
A specialized kind of malware that gathers information about the users actions and data and reports it back to its developers or other agency. Spyware is often (but not always) engineered to be as invisible or inconspicuous as possible.