What happens when you type holbertonschool.com in your browser and press Enter

DNS Request

Each time a URL in your preferred browser this request will be made. The Domain Name System (DNS) will filter the domain name you requested, in this case www.holbertonschool.com, find the IP address associated with that domain, the browser takes the request and breaks down the URL by parts, the first www.holbertonschool.com which is the domain name, if the browser does not know it is because it is not stored in its cache if it has never been searched is asked the DNS for the IP address that corresponds to this domain ,
the reason this happens is because we can’t expect people to remember all the IP addresses for all the different websites out there.

The DNS request goes through the resolver and this is our internet service provider but finds the IP in its cache requests the TLD server(top-level domain) in this case our top-level domain is “.com”. If this TLD server does not know the IP, it points the resolver to the authorized name servers for this domain name. There is usually more than one name server attached to a domain name, but either of these provides the IP of the domain to which they are connected. Now that you have the IP address, you can send it back to the browser that made the request to the corresponding server.

TCP/IP

TCP/IP is data transfer protocol, There are many protocols when you use the internet. TCP is a Transmission Control Protocol that sends data to the internet with some layers of integrity check so it slower than UDP just like walking in a foreign country checking your surrounding to make sure each step counts.

The Firewall

Here’s the layer of security between you and the Internet, Firewall is a network security system that monitors and controls inbound and outbound network traffic based on default security rules. A firewall typically establishes a barrier between a trusted internal network and an untrusted external network, such as the Internet.
In this case, the IP corresponding to the domain name passes through the TCP/443 port supported by the firewall for the HTTPS protocol.

HTTPS PROTOCOL

Now that the browser has the IP address, will take care of the other part of the URL, the https: // HTTPS part means Secure Hypertext Transfer Protocol and is the normal secure version of HTTP, the HTTPS protocol is secure entry to the site by port 443(HTTPS — Port 443) this transfer protocol defines various types of secure requests and responses, that is, the main way to transfer data between a browser and a website. HTTP and HTTPS requests include GET, POST, PUT, and others. HTTPS requests and responses are encrypted, ensuring to users that their data (passwords, emails, messages, etc.) cannot be stolen or used by third parties.

Load-balancer

Load balancers are all about traffic control, here the data will be analyzed and moved accordingly to ensure the overall state of the system.
Load balancers are generally used when traffic is consistent on websites and does not provide a single server. in addition to that it would create a single point of failure (SPOF). because it would only need an attack on that server to bring down the entire site.
There are many algorithms for the load balancer depending on how you want to manage data traffic on the website, example of algorithms that we can use are round-robin, which distributes requests by alternating between all servers uniformly and consistently, or the lowest connection, which distributes requests according to the current server. Loads.

Database

This is what it seems all of the data that will be presented to clients is stored in the database. and can be access using query type languages to filter and find data you want. However this clients only have read privileges for the data, the people who have the write privileges are only the people who maintain the website.

Web server

A web server is server software, or hardware that can satisfy client requests on the World Wide Web. A web server can, in general, contain one or more websites. A web server processes incoming network requests over HTTP and several other related protocols.

Application server

The web server is the basis of any web page, but most websites are dynamic. That means it is possible to interact with the site, save information on it, log in with a username and password, etc.
And this is made possible by the application server, these are responsible for bringing the software to interact in applications, communicating databases, managing user information and other actions, working behind the web server and will be able to serve a dynamic application using static content from the web server.