Java
Java is a high-level, third generation programming language, like C, FORTRAN, Smalltalk,
Perl, and many others. You can use Java to write computer applications that crunch
numbers, process words, play games, store data or do any of the thousands of other
things computer software can do. Compared to other programming languages, Java is
most similar to C. However although Java shares much of C's syntax, it is not C.
Knowing how to program in C or, better yet, C++, will certainly help you to learn
Java more quickly, but you don't need to know C to learn Java. Unlike C++ Java is
not a superset of C. A Java compiler won't compile C code, and most large C programs
need to be changed substantially before they can become Java programs. What's most
special about Java in relation to other programming languages is that it lets you
write special programs called applets that can be downloaded from the Internet and
played safely within a web browser. Traditional computer programs have far too much
access to your system to be downloaded and executed willy-nilly. Although you generally
trust the maintainers of various ftp archives and bulletin boards to do basic virus
checking and not to post destructive software, a lot still slips through the cracks.
Even more dangerous software would be promulgated if any web page you visited could
run programs on your system. You have no way of checking these programs for bugs
or for out-and-out malicious behavior before downloading and running them. Java
solves this problem by severely restricting what an applet can do. A Java applet
cannot write to your hard disk without your permission. It cannot write to arbitrary
addresses in memory and thereby introduce a virus into your computer. It should
not crash your system.