Cybersecurity Fundamentals

It is the habit of questioning assumptions instead of accepting them. Where a builder asks how a system should work, an attacker asks how it can be made to work for them: what does this system trust, and what happens if that trust is wrong? The same question applies to a login form, a network service or a person.

Confidentiality, integrity and availability. Confidentiality means only the right people can read the information, integrity means it is correct and untampered, and availability means the system is there when it is needed. Running any system through all three is a reliable way to spot what could go wrong.

A vulnerability is a weakness that could be misused, like an unlocked window. An exploit is the specific technique that misuses it, like climbing through that window. A threat is who might do it, and risk is how likely and how damaging the whole combination is.

Not to begin. Logical thinking matters more than advanced maths, and you can learn a great deal before writing any code. Comfort with the command line and a little scripting makes you much faster, which is why Linux basics appear early in most learning paths, including this course.

Because watching feels like progress but doing is progress. The format is read the idea, see the method, then do it yourself in the lab, with a worked solution available when you are stuck. Hands-on practice is where command-line and security skills actually stick, so most of your time is spent at the keyboard.

Threat modelling is looking at a system in a structured way to decide what could go wrong and what to fix first. A quick version needs only paper: draw how data flows, mark where it crosses from untrusted to trusted, list what crosses, ask what happens if each item is hostile, map each worry to confidentiality, integrity or availability, then rank by likelihood and impact.