Web Server terms and definitions such as virtual space, domain name resolution, a record, MX record, cname record, and TTL

Web Server terms and definitions such as virtual space, domain name resolution, a record, MX record, cname record, and TTL
Terms for renting space and website servers
What is a domain name server?
Domain Name Server (DNS server) is the server that provides domain name resolution. It is generally provided by the upper-layer server provider.
What is domain name resolution?
Domain name resolution is the process of converting the domain name to the IP address. An IP address is a digital address that identifies your site on the Internet. To make it easy to remember, use a domain name instead of an IP address to identify the site address. Domain name resolution is completed by the DNS server.
What is a record?
The A (Address) record is used to specify the IP address record corresponding to the Host Name (or domain name. You can direct the website server under this domain name to your web server. You can also set a second-level domain name for your domain name.
What is an MX record?
The mail route record. You can direct the mail server under the domain name to your own mail server, and then you can control all mailbox settings on your own. You only need to enter the IP address of your server online to transfer all emails under your domain name to your own email server.
What is a cname record (alias record )?
That is, the alias record. This record allows you to map multiple names to the same computer. It is usually used on computers that provide both WWW and mail services. For example, there is a computer named "host.mydomain.com" (a record ). It provides WWW and mail services at the same time, in order to facilitate user access to the service. You can set two aliases (cname) for the computer: WWW and mail. The two aliases are www.mydomain.com and "mail.mydomain.com ". In fact, they all point to "host.mydomain.com ".
What is the TTL value?
The full name of TTL value is "time to live". Simply put, it indicates the cache time of DNS records on the DNS server. To understand the TTL value, take a look at the following example:
Assume that the IP address of the domain name myhost.abc.com (in fact, this is a DNS record, which usually indicates that there is a host named myhost in the abc.com domain) is 1.1.1.1, and its TTL is 10 minutes. This domain name or record is stored on a DNS server named dns.abc.com.
Now there is a user in the browser to type the address (also called URL): http://myhost.abc.com what will happen at this time?
The DNS server specified by the visitor (or its ISP, Internet service provider, which is dynamically allocated to him) 8.8.8.8 tries to explain myhost.abc.com to him, of course, because the DNS server 8.8.8.8 does not contain the message "myhost.abc.com", it cannot be resolved immediately. However, after recursive queries by global DNS, the DNS server "dns.abc.com" is finally located, dns.abc.com: the DNS server sends the IP address 1.1.1.1 of myhost.abc.com to 8.8.8.8. However, 8.8.8.8.8.8 tells the user the result. 8.8.8.8 in order to accelerate the resolution of the myhost.abc.com record in the future, the 1.1.1.1 result will be retained for a period of time. This is the TTL time, during this period, if the user has another resolution request for the myhost.abc.com record, it will directly tell the user 1.1.1.1. When the TTL expires, the above process will be repeated.
What is the primary domain name of a virtual space?
The domain name bound to the purchased virtual space. The domain name directs to the virtual space purchased by the customer. Once specified, the domain name cannot be changed.
This domain name can be a free second-level domain name or top-level domain name applied for by some service providers, or a usable domain name applied for by the customer to other institutions.
What is a free second-level domain name?
Some service providers provide a certain number of top-level domain names for customers to apply for free second-level domain names. The free second-level domain name applied by the customer can be used as the primary domain name of the virtual space purchased by the customer, you can also use the domain name appending function provided by some service providers to use the alias of the primary domain name or change the direction of the primary domain name for the free second-level domain name applied for by other service providers. The General Service Chamber of Commerce is responsible for parsing the free second-level domain name you apply.
What is an alias and a change direction?
For each accessed domain name, you can change its webpage content. If you select "change to", the system will automatically
Forward to the specified folder. If you select "alias", the system displays the specified folder as the existing folder. "Change
The difference between "alias" and "alias" is whether the address to be changed.
For example, if you append the domain name test.ad0.cn, set the path to/test.
Whether you set the append domain name as an alias or change the direction,
Enter test.ad0.cn in the address bar to access the content under your primary domain name/test /.
The difference is that test.ad0.cn is displayed in the address bar when it is set as an alias.
Test.ad0.cn/test/
What is domain name appending (alias appending )?
Some service providers provide the domain name append function, that is, to append an alias to the primary domain name of a virtual space (the premise is that the virtual space has been purchased ). You can apply for a free second-level domain name or other available domain names as aliases from the service provider.
What is a virtual host? Why?
Virtual Host Virtual Server (VM) uses special hardware and software technologies to divide a Computer Host into a "virtual" host, each VM has an independent domain name and IP address (or shared IP address), and has a complete Internet server function. Different servers opened by multiple users are running on the same hardware and operating system. Program Each user has a part of the system resources (such as IP addresses, file storage space, memory, and CPU time ). Virtual Hosts are completely independent. in the outside world, each virtual host performs exactly the same as an independent host.
The emergence of virtual host technology is a major contribution to Internet technology and a good news for Internet users. Because multiple virtual hosts share the resources of a real host, the hardware cost, network maintenance cost, and communication line cost for each user are greatly reduced. Internet is truly an affordable network for everyone! Almost all American companies (including some families) now have their own web servers on the network, and a considerable part of them use virtual hosts!
What can a VM do?
Different services provide different VM services.
For example, PHP, CGI, and database mounting are supported. You can easily manage your website through a browser:
A) generate various statistical reports, website access statistics, and various logs as required.
B) back up and restore website data (including databases) by yourself ).
C) Create your own email account and email list.
D ).....
What is a CGI program?
CGI is the abbreviation of Common Gateway Interface. It is a program used by the server to communicate with users. It can make your webpage more vivid, many tools on the network, such as search engines, message boards, and BBS, are CGI programs. The extension of the CGI File Name is. cgi or. pl.
Can I run CGI programs on a VM?
Please consult your service provider.
What is a web space?
A web space is the space used to store website page content.
What is log?
When the user's Vm is working, the WWW access results are recorded in some log files at all times, they record the information such as the time, the files accessed by the client, and the transfer success. However, the number of such information entries is large, and it is difficult for users to directly obtain intuitive results from the log file, generally, the service provider installs the access statistics software on the server. After processing the user's log files, the service provider obtains the following information: in the past period (for example, one week or one month ), the number of user's virtual hosts that have received this access, the maximum number of accesses from the people, the maximum number of accesses to the content, the daily situation, and the maximum number of visits per day. information, the results can also be displayed through a color stereo histogram.
What are the restrictions on using a VM?
Different service providers have different restrictions, such:
Spread undesirable emails (spaming) or post inappropriate comments in newsgroups;
Run programs or processes unrelated to the Web server, including IRC, newsgroup, and others;
Compile (compile;
Conduct political propaganda and spread of pornography and content;
Do anything that tries to change the system configuration or undermine system security.
What is a static IP address?
Static IP addresses are independent IP addresses.
What is spam?
Spam refers to the use of email on the Internet to broadcast advertising. This behavior adds a large amount of irrelevant or useless information to the mailboxes of many people, so it is becoming more and more disgusted. This is already illegal in the United States.
What is anonymous FTP?
Anonymous FTP means that when you log on to the FTP server, the user name uses "anonymous" and the password is your own email address. It can be seen that anonymous FTP is open to any user, but the user's permissions after logon are very low. Generally, only files can be uploaded from the server, rather than uploading or modifying the content on the server. It can effectively help the website owner provide files or software for users on the Internet to download.
What is an access statistics report?
When a user's "virtual host" is working, the WWW access results are recorded in some log files at all times, they record the information such as the time, the files accessed by the client, and whether the information is successfully transferred. However, the number of such information entries is large, making it difficult for users to directly obtain intuitive results from the log file. To this end, we have installed Advanced Access statistics software on the server, which processes the user's log files and obtains the following information: in the past period (for example, one week or one month ), the user's "virtual host" can be accessed many times, where the user accesses the most frequently, what content is accessed the most frequently, how is the situation every day, and how many times a day is accessed. information, the results can also be displayed through a color stereo histogram.