Q: What is an IP address?
An IP address is a unique number that serves two purposes:
- It identifies your computer.
- It provides information about where your computer is located.
You can think of an IP address as the digital equivalent of a physical address for your house or a P.O. Box for your mail. Every computer connected to the internet has an IP address.
More generally, each computer within a network is identified by an IP address. For example, if your computer is a part of your home network, it will be recognized on your network with an IP address. This IP address may not be the same as the one assigned when your computer joins the global network called the internet.
Example IP address: 184.108.40.206
Q: What is a domain name?
A domain name is a human-readable address that uniquely identifies a computer.
Because computers don't really recognize domain names, domain names have to be converted into IP addresses before they can be used by the computer. This conversion is done by a domain name server (or DNS server). This is essentially a massive database that maps domain names to IP addresses, a process called DNS name resolution.
Example domain name: WebsiteBuilders.com
Q: What is a computer name (or hostname)?
The computer name (sometimes referred to as the hostname) is a human-readable name assigned to a computer or server.
Computer names are optional since only the IP address is required to identify a computer, but such names are more accessible for people to use and remember.
Example hostname: mail.consumer.net
Q: What is Ping?
Ping is a simple program that allows you to check two things:
- A specific IP address exists
- The IP address can accept incoming requests
Most computers come with ping installed by default. You can access it by going to the Terminal or Command Prompt window and typing
ping <IP address>
Ping performs both checks by sending signals (in the form of packets) the computer represented by the IP address you provide to see if that computer sends a response.
If the receiving computer does not respond at all, the transaction is said to timeout. This indicates that the computer isn't connected to the internet (or, at the very least, unreachable).
Note that Ping can only verify that a computer is connected to the internet; it can validate neither email addresses nor specific web pages.
Q: What is a Lookup?
Lookup is the process of getting a hostname for a given IP address or getting an IP address for a given hostname.
For example, you could perform a lookup to determine that www.consumer.net is associated with 220.127.116.11 (or vice versa).
Please note that such lookups only work with names that have been registered (for example, if you purchased a domain name like example.com, the company from which you bought the domain name would have taken care of registration on your behalf). You might name your computer Joe, but you would not be able to do a lookup for Joe using your local network IP address.
Q: What is Traceroute? What is a trace?
Traceroute (a.k.a. tracert on some operating systems) is a tool that allows you to track (or trace) the path taken by a packet on a network. You can see all of the servers through which the packet passes, beginning with your computer (or whatever your set as the origin point) and ending with the destination computer.
As the packet travels, it moves through multiple servers. Each move from one server to another is called a hop. Traceroute records the amount of time each hop takes.
By obtaining information about how a packet travels, as well as how long it takes to go from place to place, you can gather information about the quality of the network, including slow points and areas of limited connectivity.
Q: What is WHOIS?
WHOIS, shorthand for who is responsible for a domain name or an IP address?, is a publicly-available tool that contains information about the parties behind various domain names.
Whenever an individual, organization, or government registers a domain name, they have to provide identifying information for someone responsible for that domain name. Such information includes things like the full name, mailing and email addresses, phone numbers, and so on. Individual registrars manage this data (e.g., GoDaddy, Domain.com) but ICANN's WHOIS protocol can be used by the general public to search the various databases.
Note that, while you are required to provide accurate information to your registrar, some companies offer you the option of purchasing domain privacy. This means that your personal information will be kept hidden from public view. What searchers will then see is the information of a forwarding service.
Q: What is a DNS Record?
As we mentioned above, DNS stands for Domain Name System, and it is the database system used to find the IP address associated with a provided domain name. The database file used to link a domain name to its IP addresses is called the DNS record.
There are several different types of DNS records, each handling a specific task. For example, address (A) records are the ones mapping a hostname to an IP address, mail exchange (MX) records help emails get sent to the right mail servers on a given domain, and canonical name (CNAME) records allow you to add aliases for your hostname.
Q: What is a DNS Server?
A DNS server is the server that contains the database of IP addresses and the hostnames (or computer names) with which they are associated.
Q: What is a Network Lookup?
A network lookup is essentially a WHOIS query that helps you determine who owns and administers a specific domain name. You'll also get contact details for that person (or the contact details of a forwarding service if that person has opted to keep their information private).
Q: What is an Express Trace?
Q: What is URL Encoding?
There are two ways a web browser might display a URL: standard or encoded.
You're probably familiar with standard URLs. They're easily read by human eyes (i.e., www.example.com). However, if there are special characters that need to be included in the URL, they need to be encoded.
For example, some websites transmit search data in the URL (such as when you search a site for something). If your search query becomes a part of the URL, and your search query includes a space, it will need to be encoded. To do this, your browser, using the ASCII key set, replaces the space with %20 (e.g., example.com/search=t%20shirt).
Q: What are HTTP Headers?
HTTP headers are a way for a client (such as your web browser) to pass information to the server (or vice versa). Either party sends these headers with requests and responses (if you're unfamiliar with HTTP, a request might be the web browser asking for a website, while the response might be the files needed to render the website. There are other types of requests and responses, but this is the one most people are familiar with).
HTTP headers can be used to send the appropriate credentials needed to access something, indicate that something should be cached for faster retrieval from the server, and so on.
Q: What is Email Validation?
In short, email validation is the process by which you check to see if a specific email address is capable of receiving email or not. Email validation is essential especially for those who maintain mailing lists and send out emails to a large number of people.
One identifying feature of spammers is that they send out mass amounts of email, with a large number of those getting marked as undeliverable. There are many reasons for this, including the possibility that many of the addresses are made up — the hope is probably that, by making a sufficient number of guesses, they will land in some valid inboxes.
As you can see, one of the distinctions between valid marketing and spamming is the validity of their email lists — the former is likely to see fewer messages fail to go through. In addition to just making sure that their means of collecting addresses weeds out incorrect options, email validation offers additional protection against email handlers (such as Gmail) marking their messages as spam.
Q: What is a Base-10 Number? What is a Base-256 number?
First things first:
- A Base-10 number looks like this: 156
- A Base-256 number looks like this: 18.104.22.168
You can convert a Base-10 number to a Base-256 number (and vice versa). For example, this website can be reached using any of the following:
Q: What is the difference between the computer name (or hostname) and the domain name?
The hostname is the name of the computer, while the domain name is a registered name that identifies a computer. The two may be identical, but sometimes, they are not. For example, you might have an internal network that refers to a server as Computer A, but the publicly-available domain name is example.com (and, it goes without saying, this is the name you would have registered).