Freeware, Shareware, Demoware, and Just Plain Stealing
When you download and install a program, you should know
whether you have permission to do so. Many programs are marked
on software listings as freeware, which means that the author
gives you permission to use the program forever for free. Other programs
are shareware, which means that if you like the program and plan
to use it, you should send the author money -- shareware programs usually
display a "nag screen" that tells you the suggested donation and the address
of the author.
A recent development is adware, which is freeware that displays
advertisement while you use it. Some adware offers you the option of paying
to register the program, which turns off the ad display.
Less useful is demoware, which are demonstration versions
of programs. They are free to use, but they are either crippled in some way
or they stop working after a month or so. If you like the program and want to
continue to use it, you have to buy it.
Finally, you may stumble across a warez (short for "softwares," we guess)
site that offers commercial software for download. These programs are offered without
the knowledge or consent of their owners (for example, it is not okay with Microsoft
to offer Microsoft Office for free download). Don't use pirated software -- it's stealing.