API – Application Programming Interface

An application programming interface (API) is a computing interface which defines interactions between multiple software intermediaries. It defines the kinds of calls or requests that can be made, how to make them, the data formats that should be used, the conventions to follow, etc.

ARPANET

Created in 1969, the Advanced Research Projects Agency Network (ARPANET), was the world’s first operational packet switching network and the core network of a set that came to compose the global Internet. The network was created by a small research team at the Massachusetts Institute of Technology and the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense. The packet switching of the ARPANET was based on designs by Lawrence Roberts of the Lincoln Laboratory.

C-block

Each website on the Web is actually an IP address and the domain name (like example.com) routes your computer to that IP address.

Hosting providers buy large blocks of IPs, so if you have a lot of websites hosted by the same provider they may be in the same c-block.

One tactic that some people have used is buying many domain names and making websites that all link to a target website that they’re trying to boost the SEO and search rankings for.

Search engines have caught on to this tactic and they’re leery of websites that have lots of inbound links from websites all in the same c-block of IP addresses – it is considered black hat SEO.

Cookie

Cookies are text files with small pieces of data — like a username and password — that are used to identify your computer as you use a computer network. Specific cookies known as HTTP cookies are used to identify specific users and improve your web browsing experience.

Data stored in a cookie is created by the server upon your connection. This data is labeled with an ID unique to you and your computer.

When the cookie is exchanged between your computer and the network server, the server reads the ID and knows what information to specifically serve to you.

Domain

A domain name is the address of your website that people type in the browser URL bar to visit your website.

In simple terms, if your website was a house, then your domain name will be its address.

A more detailed explanation:

The Internet is a giant network of computers connected to each other through a global network of cables. Each computer on this network can communicate with other computers.

To identify them, each computer is assigned an IP address. It is a series of numbers that identify a particular computer on the internet. A typical IP address looks like this:

66.249.66.1

Now an IP address like this is quite difficult to remember. Imagine if you had to use such numbers to visit your favorite websites.

Domain names were invented to solve this problem.

Now if you want to visit a website, then you don’t need to enter a long string of numbers. Instead, you can visit it by typing an easy to remember domain name in your browser’s address bar.

IP-address

An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. An IP address serves two main functions: host or network interface identification and location addressing.

Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. However, because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP (IPv6), using 128 bits for the IP address, was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s.

IP addresses are written and displayed in human-readable notations, such as 172.16.254.1 in IPv4, and 2001:db8:0:1234:0:567:8:1 in IPv6. The size of the routing prefix of the address is designated in CIDR notation by suffixing the address with the number of significant bits, e.g., 192.168.1.15/24, which is equivalent to the historically used subnet mask 255.255.255.0.

The IP address space is managed globally by the Internet Assigned Numbers Authority (IANA), and by five regional Internet registries (RIRs) responsible in their designated territories for assignment to local Internet registries, such as Internet service providers (ISPs), and other end users. IPv4 addresses were distributed by IANA to the RIRs in blocks of approximately 16.8 million addresses each, but have been exhausted at the IANA level since 2011. Only one of the RIRs still has a supply for local assignments in Africa. Some IPv4 addresses are reserved for private networks and are not globally unique.

Network administrators assign an IP address to each device connected to a network. Such assignments may be on a static (fixed or permanent) or dynamic basis, depending on network practices and software features.