We uses large amount of information everyday. It may be in our computer systems, mobile devices or in our brains!. Do you know how much data we handle in one day? It is huge, it is larger than the detailed information about the human evolution till 2000!
Information are arranged in a manner that, it can be retrieved easily from the resources. Computer systems and mobile devices can access and handle various information resources easily.
Computer systems and mobile devices are handling the information by using various mechanisms including authentication, synchronization etc.
Authentication mechanisms, yes, like the passwords and usernames. Authentication mechanisms works under the basis of some unique secret codes, it may be a secret word, fingerprint, or even in the form of pills!

Why We Use These Authentication Mechanisms ?

Because, we need to protect our data from others.

3 Main Reasons why Information Security Is Important

Usually our data are stored and protected by some authentication mechanisms. But in some cases these authentication mechanisms can be overridden. That means, our data can be viewed or controlled by other persons (hackers) or organizations.
The above mentioned situation is of course scary. So we must defend the information from unauthorized access. Yes, the Information Security.
3 Main Reasons are here,

1. Availability

Information security provides availability as it’s quality. Availability is one of the great qualities of information security.

What is availability, can you explain it with an example ?

Of course, let me take an example from the hacking world, i think it will be easier for you to understand the concepts.
When hackers performs denial of service attacks on a website or network, the website or network cannot be accessed by a normal user. That is called the non availability of service. If the website or network are have enough security, when the hackers perform denial of service attacks, the hackers will be banned from the network or website and a normal user access it. That is called Availability.
Availability = can have whenever needed.

2. Confidentiality

Confidentiality is also one of the qualities of Information Security. Actually, the meaning of this word is in the word. I mean “confidential-ity“.

Can you explain it using a simple example ?

Yes, confidentiality means private information or secret information. As you know that, everyone have secrets, it may be their private phone number,private photos or anything.
Just imagine, you have a private file stored in your computer or cloud. One day you wake up realizing that your private information has been stolen and it’s now available in every public resources. I know, it is scary.
To prevent others from accessing your private information , you need tight security. That is, you need confidentiality !

3. Integrity

The term integrity means, maintaining and assuring the accuracy and consistency of data. Data integrity ensures data is recorded exactly as intended.

Can You Explain Integrity With An example ?

Let’s take an example, just imagine, you have uploaded a file to a server. After two days you have downloaded the same file and realize that, some part of original file is missing or corrupted. That’s why we need integrity. Integrity is the opposite of data corruption or data loss.
Any unintended changes to the data as a result of storage, processing, retrieval or malicious intent is the failure of data integrity. May be a human error (I mean error’s caused by humans) can cause failure of data Integrity.
The above mentioned Availability, Confidentiality, Integrity are the basic concepts of information security. In 2002, Donn Parker proposed an alternative model called the six atomic elements of information, which consists of confidentiality, possession, integrity, authenticity, availability, and utility. But this theory is still a subject of debate among security professionals.