Addi's response covers this pretty well, so I will not repeat what he has said. Let me add a few points though (largely from an historical perspective), that might help your understanding and that of others who might be reading this thread and are a bit confused:
There are plenty of non-Sun variations of the Unix operating system (that has actually been a problem historically for Unix, since multiple versions have fragmented the market), and one can utilize the Internet via any of them or, for that matter, many other operating systems (such as IBM's MVS and OS/2, DEC's VMS, Microsoft's Windows NT, Apple's MAC OS and presumably Rhapsody). Sun's version of Unix (called Solaris) is currently available for Sun hardware and for the Intel X86 (PC) architecture, and is well established as a platform for networking, including via the Internet. It is possible to run (a limited number of) other operating systems on Sun hardware. The current models of Sun hardware are based on SPARC processors, but previous generations have been based other chips (including Intel's and Motorola's, a la PC's and Apple Macintoshes).
The Internet is just a big network (protocols, especially TCP/IP, and some hardware). Overlaid on top of it are services like the World Wide Web, e-mail, chat, and usenet. Creation of the World Wide Web (and HTML, the language it uses), along with the government's release of control over the Internet, has led to an explosive boom in use of the Internet. But don't ever forget that the Internet can be used generally for the transfer of a wide variety of information (e.g. audio, video, etc.), and not just for Web pages.
Java is a Sun-created language that is extremely useful, especially in relation to the Internet (IMHO and apparently also in the opinion of Microsoft, Intel, DEC, and CPQ, as they said in their open letter to Sun this week). Reasons for the importance include platform-independence (i.e. like the Internet itself, it is not wed to a particular computer architecture or operating system), security (this is important especially because much of the information flowing over the Internet is anonymous, and it is difficult to verify the source of the other information), and relative ease-of-use (Java includes features that make programming easier and less bug-prone than some alternatives, as well as features that integrate it well with network use). Right now I think it is fair to say that Java is the most popular network-based language, but it is not the only way things can be done. Active-X is one alternative being pushed by a well-known software company based near Seattle.
Java, as a general purpose language, also seems useful in other contexts like (notably) smart-cards.
All of this is just my take on things, and I don't purport to be an expert. No guarantees, but I hope it helps.
JMHO. |
