Introduction

The first proposal of a hypertextual system can be traced back to the studies of Vannevar Bush, later published in the article As We May Think of 1945. The concept of hypertext was introduced in 1965 by Ted Nelson.
The creators are Tim Berners and Robert Cailliau, who started from the principle that the exchange of information on the network had to be simple, intuitive and fast, to allow researchers from all over the world to communicate and cooperate with ease and efficiency. In this project the technological development of the telecommunication networks has played a very important role, the travel documents on the net at ever higher speeds.
At the base of the Web there are two fundamentals which are HTML and HTTP.
HTML means Hyper Text Markup Language, it is a language, ie a real language with its own grammatical and syntactic rules, this set of rules must be made and decipher hypertext documents. These documents can be linked together with appropriate references, not necessarily reciprocal, and enriched with images, texts, sounds, or other multimedia resources, creating what in jargon are called Web Pages or HTML.
The second concept underlying the World Wide Web is HTTP which means Hyper Text Transfer Protocol, that is to say the protocol, the rules, for the transfer of hypertext documents over the network.

IT security is the set of means, technologies and procedures aimed at protecting IT systems in terms of availability, confidentiality and integrity of IT assets or assets. An often used synonym is cybersecurity, a term that more precisely represents a subclass being that area of IT security that depends only on technology: with it the qualities of resilience, robustness and reactivity that a technology must possess in order to face attacks aimed at compromising its correct functioning and performance (cyber attacks) are often emphasized. Cryptography is a fundamental tool in the fight against cybercrime.

Encryption is based on an algorithm and a cryptographic key. In this way the confidentiality of the information is guaranteed, which is one of the essential requirements in the field of IT security, thus preventing the implementation of different types of IT attacks on confidential data (eg sniffing). The reverse study approach aimed at breaking a cryptographic mechanism is called cryptanalysis which represents the other branch of cryptology. Crucial are also the time required for cryptanalysis to decrypt the message: for various telecommunications and IT applications, a system can be considered secure even if its encryption system is violable, but with realization times that would make subsequent attempts to direct attack.

The current cryptographic research, having solved the theoretical problem of guaranteeing security, is dedicated to overcoming the aforementioned strong limits of use. More convenient but nevertheless extremely safe methods are sought which, if possible, use short and reusable keys without compromising their usefulness. At the moment there is no cryptographic technique that can be defined as secure in an absolute sense, except the Vernam cipher; all other techniques secure the data only for a certain period of time and cannot guarantee the duration of the secrecy.

The web is a door opened to new information, but also to meeting new people. It can literally open our computer to other people. Websites and web applications are just as prone to security breaches as physical homes, stores, and government locations.
Computer crimes are those crimes committed with the use of computers and, mainly, with the Internet. These crimes range from server sabotage, to the theft of information and money online, to cyberbullying.
Web security is also known as “Cybersecurity”. It basically means protecting a website or web application by detecting, preventing and responding to cyber threats.

There are several methodologies and technologies to protect yourself, but the most important is knowledge.
Understanding what the Internet is and how it works can help you understand the dangers we are exposed to.
In order to learn what a phishing e-mail to a computer virus is and, simply, to be careful to open the attachments of our e-mails. But among the many attentions there is to learn how to preserve one's privacy, so as to prevent malicious people from approaching us.

The Internet and the Web are the new wonder of this generation and it is important for all of us to know it better in order to get the best out of it.