What is Linux? What is the difference between it and UNIX? Most of the reasons for this question are that you went to the lab when you were a freshman and saw a senior student answer questions on a machine with a large screen. You looked at him with envy, q: "What is this computer, so advanced?" He said proudly, "this is Unix ". Later, you know much about it. You know it's a Sun workstation, and it's running Solaris, it's UNIX. Now you have heard that Linux is also Unix. Why? Don't be afraid of Linux first. "What about Linux" provides a detailed explanation for those who are keen on Linux.
I. Differences and connections between Linux and UNIX
Simply put, it can be said that Linux's open-source is free, and users can download it online. UNIX is a commercial charge. Generally, when sellers sell machines, they will be equipped with Unix systems, for example, sun's Solaris.
Unix was an operating system that was commercialized by a large company 20 or 30 years ago after several graduate students started in the lab. It grew and occupied the market. At that time, it was only running on expensive machines that only the university could afford one or two. Later, there were more machines, more companies, and more people to know, so they split their families. The "Unix" name was due to legal relations, no one can say that their operating system is "Unix" but "UNIX compatible. So now the "Unix" system does not exist, and there is only a distant legend. So What Are Solaris, Aix, and Iris now? All these are commercial Unix systems developed by companies on their hardware. These systems all follow an odd POSIX standard. By the way, this standard is too messy, programming interfaces and even commands are different, so there is no way to discuss a protocol.
So what is Linux? Linux is a UNIX-Compatible System Based on PC (also supported by other platforms). It is no longer compatible with any other UNIX systems in terms of UNIX. So if you have the idea that "Solaris is an orthodox UNIX, Linux is only compatible", I'm sorry you are wrong. At least you have to defeat anyone who supports Aix, they also think that AIX is the Orthodox UNIX. Therefore, you can learn about UNIX in Linux, which is mostly used in other businesses.
UNIX can be used. Of course, the core idea is absolutely the same. So three years ago, only your doctoral counselor had the opportunity to go to the baby sun in the lab. Now you can practice it on a PC, isn't that a wonderful thing?
UNIX and Linux on some PCs are similar in implementation. Almost all commercial UNIX versions basically support the same software, programming environment, and network features. However, there are still many differences between commercial Linux and UNIX versions.
Linux supports different hardware scopes than commercial UNIX. Generally, commercial Unix supports more hardware, but Linux supports more hardware.
Note that Linux is at least as stable as commercial UNIX.
For many users, the most important factor is price. Linux is a free software that can be downloaded from the Internet. If the Internet access is inconvenient, you can obtain the Linux disk or CD-Rom through mail order very cheaply. Of course, you can also get it directly from your friends.
The value of commercial Unix should not be devalued. In addition to the price of the software, you also need to pay the documents, after-sales support and quality assurance fee. These are important for large organizations, but PC users may not benefit from them. Many commercial companies, universities, and other organizations have found that running Linux on cheap pcs in laboratories is better than running commercial UNIX on workstations. Linux can provide the workstation function on a PC, and the price of a PC is a fraction of that of a workstation.
There are also some cheap UNIX for PC, the most famous of which is ipvbsd. In many aspects, the iisbsd package is compatible with Linux, but Linux is more suitable for user needs. Most importantly, Linux development is open, and any volunteers can contribute to the development process. In contrast, objective BSD is developed by closed teams. In this way, there is a serious conceptual and Design difference between the two products: the objective of Linux is to develop a complete UNIX system from the beginning; objective of objective BSD is to modify the existing BSD to fit the 80386 system.
Ii. Differences between Linux/Unix and windows
Like Linux, Windows is a fully multitasking operating system. They support the same user interface, network, and security. However, the real difference between Linux and Windows is that Linux is actually a unix version, and the contribution from UNIX is huge. What makes UNIX so important? UNIX is not only the most popular Operating System for Multi-User Machines, but also the basis of free software. On the Internet, a large number of free software is written for UNIX systems. There are many UNIX vendors, so there are also many UNIX implementation methods. No individual organization is responsible for Unix distribution. At present, there is a huge force to promote the standardization of UNIX community in the form of an open system. On the other hand, Windows is a dedicated system, which is designed by the company that develops the operating system. In this sense, this company is very profitable because it sets strict standards for program design and user interface design, which is totally different from those of open system communities. Some organizations are trying to standardize Unix programming interfaces. In particular, Linux is fully compatible with the posix.1 standard.
Security issues require long-term attention for IT administrators. Supervisors need a framework to reasonably evaluate the security of the operating system, including basic security, network security, and protocols, application Protocols, publishing and operations, validation, trusted computing, and open standards. In this article, we will compare the security of Microsoft Windows and Linux according to these seven categories. The final qualitative conclusion is: so far, Linux provides better security performance than Windows, with only one exception (reliability ).
Regardless of the criteria used for Windows and Linux evaluation, there is a certain problem: each operating system has more than one version. Microsoft's operating systems include Windows 98, Windows NT, Windows 2000, Windows 2003 Server, and Windows CE, while the Linux release version is based on the kernel (2.2, 2.4, 2.6) the differences are also quite different from those in software packages. The operating systems we use in this article are the current technologies rather than the "old" solutions.
Users need to remember that there is a philosophical difference between Linux and Windows. Windows OS tends to integrate more functions into the operating system and combine programs with the kernel. Linux is different from windows, its kernel space has obvious limitations with the user space. Depending on the design architecture, both of them can make the operating system more secure.
We hope that you will not explore the differences between operating systems in the future, nor be too deeply poisoned by Windows ideas. A professional computer engineer must be able to afford windows, you can learn Linux in the future.
3. Do not compare windows with Linux