What happens when you type google.com in your browser and press Enter
What is the internet ?
For many people, how the internet works is a mystery. The reality is actually quite simple.
The internet is essentially a huge network of cables connecting computers around the world so that they can share information and communicate with each other. Information is sent from a computer, translated into small packets of data and transmitted over a mixture of traditional copper cables, newer fiber optic cables, wireless radio waves or satellites. Once transmitted to their destination, the data packets are reassembled and translated back into information that you — the human being in front of the computer accessing the Internet — can understand.
What is a website ?
A website is, in simple terms, a set of files created in HTML (hyper text markup language), which is the code used to structure a web page and its content. The website is stored on a dedicated computer called a server. Servers have the power and storage space to store many files, and can be stand-alone machines or part of a large data farm. A server’s files are accessible to other computers via a network connection (such as the internet) through its own numerical address, called an IP address. As of June 2021, there were 1.86 billion websites on the internet, stored on millions of servers around the world. It is estimated that Google operates on 1 million servers.
What is an IP address ?
An IP address is a unique address that identifies a device on the internet or a local network. IP stands for “Internet Protocol,” which is the set of rules governing the format of data sent via the internet or local network.
In essence, IP addresses are the identifier that allows information to be sent between devices on a network: they contain location information and make devices accessible for communication. The internet needs a way to differentiate between different computers, routers, and websites. IP addresses provide a way of doing so and form an essential part of how the internet works.
What happens when you type a URL in a browser ?
Now that you know the fundamentals of the Internet, what happens when you type a URL into a browser? The Domain Name System (DNS) is what happens.
The DNS is the directory service of the Internet and contains the correspondence between domain names and IP addresses (DNS records), much like a telephone book. The DNS records are distributed in a multitude of linked databases and are searched when you type a URL in a browser. Since you don’t want the lookup to be slow every time you visit a website via its URL, the lookup process follows this routine to speed it up:
1 -Your browser’s cache (stored records) is checked first.
2- Your operating system’s cache is checked
3- Your router’s cache is checked
4- Your Internet Service Provider’s (ISP) cache is checked.
Once the URL is found, your browser displays the website.
DNS request :
DNS is a global system for translating IP addresses to human-readable domain names. When a user tries to access a web address like “example.com”, their web browser or application performs a DNS Query against a DNS server, supplying the hostname. The DNS server takes the hostname and resolves it into a numeric IP address, which the web browser can connect to.
A component called a DNS Resolver is responsible for checking if the hostname is available in local cache, and if not, contacts a series of DNS Name Servers, until eventually it receives the IP of the service the user is trying to reach, and returns it to the browser or application. This usually takes less than a second.
Transmission Control Protocol/Internet Protocol (TCP/IP) is the language a computer uses to access the internet. It consists of a suite of protocols designed to establish a network of networks to provide a host with access to the internet.
TCP/IP :
TCP/IP is responsible for full-fledged internet data connectivity and transmitting the data end to end by providing other functions, including addressing, mapping and acknowledgment. TCP/IP contains four layers, which differ slightly from the OSI model.
HTTPS/SSL :
SSL is an acronym for Secure Sockets Layer. A type of digital security that allows encrypted communication between a website and a web browser. The technology is currently deprecated and has been replaced entirely by TLS.
TLS stands for Transport Layer Security and it ensures data privacy the same way that SSL does. Since SSL is actually no longer used, this is the correct term that people should start using.
HTTPS is a secure extension of HTTP. Websites that install and configure an SSL/TLS certificate can use the HTTPS protocol to establish a secure connection with the server.
- The goal of SSL/TLS is to make it safe and secure to transmit sensitive information including personal data, payment or login information.
- It’s an alternative to plain text data transfer in which your connection to a server is unencrypted, and it makes it harder for crooks and hackers to snoop on the connection and steal your data.
- Most people are familiar with SSL/TLS certificates, which are used by webmasters to secure their websites and to provide a secure way for people to carry out transactions.
- You can tell when a website is using one because you’ll see a little padlock icon next to the URL in the address bar.
Load balancing :
Load balancing is a key component of highly-available infrastructures commonly used to improve the performance and reliability of web sites, applications, databases and other services by distributing the workload across multiple servers.
Web server :
A web server stores and delivers the content for a website — such as text, images, video, and application data — to clients that request it. The most common type of client is a web browser program, which requests data from your website when a user clicks on a link or downloads a document on a page displayed in the browser.
A web server communicates with a web browser using the Hypertext Transfer Protocol (HTTP). The content of most web pages is encoded in Hypertext Markup Language (HTML). The content can be static (for example, text and images) or dynamic (for example, a computed price or the list of items a customer has marked for purchase). To deliver dynamic content, most web servers support server‑side scripting languages to encode business logic into the communication. Commonly supported languages include Active Server Pages (ASP), Javascript, PHP, Python, and Ruby. (nginx souce)
Database :
A database is an organized collection of structured information, or data, typically stored electronically in a computer system. A database is usually controlled by a database management system (DBMS). Together, the data and the DBMS, along with the applications that are associated with them, are referred to as a database system, often shortened to just database.
Data within the most common types of databases in operation today is typically modeled in rows and columns in a series of tables to make processing and data querying efficient. The data can then be easily accessed, managed, modified, updated, controlled, and organized. Most databases use structured query language (SQL) for writing and querying data. (Oracle)
