If you have no idea what "Shareware" acutally means, then please continue reading.
There are probably many different forms of shareware - here we explain how we at J-M-S handle it.
Shareware is usually software (e.g. a program), which is freely available. The shareware author does expect any kind of payment from you for testing the shareware. You can obtain the shareware from CDs, from the internet, more or less anywhere you like (as long as it is the shareware version).
If you do not like a specific shareware program, just remove it from your system and forget about it. Or tell the author why you don't like it and what sort of improvement you would prefer.
If you do like the shareware product, then you should register it. You support the author by doing this, and increase the likelyhood, that the author will continue develop and improving the program or maybe create other shareware products you may like to see. In most cases, you also qualify for support in case you have technical questions (who likes to work for free all the time?). And, after registration, you have a legal copy of the program running on your system.
As long as a shareware product is not registered, it may be fully functional, or there may be restrictions. If it is fully functional, the author trusts in your honesty and assumes, you will pay the registration fee to support him.
Various restrictions are possible: for example, various shareware products can only be used for a given amount of time, say, 30 or 60 days - after this time, you have to register or remove it. Well, after one month of free testing you surely will know whether you find the product useful or not.
Another restriction could be, that you are only able to use a limited set of lessions of a learning program, to be able to create only a limited amount of entries in database or collector's software etc. However, you will still be able to see if you like to product and if it does what you expect it to do.
Often, you only see a small pop-up-window (called nag-screen) which just opens up every time you start the program to remind you how to register. As soon as you registered, the window will disappear in the future.
If you want to register a shareware product (you can register through us, J-M-S, all the programs on the registration pages), then you usually receive a personal registration key (a combination of letters and numbers) which you type into the program. Sometimes, it is a registration file which you just place in the directory where you installed the product. Sometimes, you receive additional files. From then on, the restrictions of the program are gone - you have a full version.
You see, it is not that difficult. The autor puts trust in you in advance and allows you to test his products, before you pay any money.