everything about linux distros
Every Git repository has at least one branch. It is called main in modern repositories and master in older ones. The branch is a movable pointer to a commit. When you commit, the branch pointer moves forward to the new commit. When you create a new branch, you create a new pointer. When you switch…
Infrastructure as Code (IaC) is the practice of managing and provisioning infrastructure through machine-readable definition files rather than manual configuration or interactive tools. Instead of logging into a server and typing commands, you write a file that describes the desired state of the infrastructure, commit it to version control, and let a tool apply it….
Terraform is the most widely used Infrastructure as Code tool. It was created by HashiCorp in 2014 and has become the standard for provisioning and managing cloud infrastructure across multiple providers. The LFCA exam places IaC and Terraform under DevOps Fundamentals, which carries 12–16% of the total weight . The study plan lists “Infrastructure as…
You have provisioned a server. It exists. It has an operating system, a network interface, and a disk. But it is not ready to run your application. It needs packages installed, configuration files written, services started, and permissions set. The work of turning a freshly provisioned server into a functioning part of your infrastructure is…
Ansible is an open-source, command-line IT automation tool written in Python. It is used to configure systems, deploy software, and orchestrate advanced IT workflows. Its defining characteristics are simplicity and ease of use: it uses a human-readable language (YAML), requires no software installed on the managed machines, and connects over standard SSH . The LFCA…
Every security decision an organization makes — which firewall to deploy, how to encrypt a disk, whether to buy redundant servers — traces back to three fundamental goals. These three goals form the CIA Triad, the foundational model for information security. The LFCA exam places this topic under Security Fundamentals, which carries 14% of the…
Authentication and authorization are two different things. They are often confused because they work together, and because both are abbreviated as “auth.” But they answer different questions. Authentication answers “Who are you?” Authorization answers “What are you allowed to do?” . The LFCA exam places this topic under Security Fundamentals, which carries 14% of the…
A Linux system never stores passwords in plain text. If it did, anyone with read access to the password file would know every user’s password. Instead, the system stores a hash — a cryptographic fingerprint of the password. When a user logs in, the system hashes the provided password and compares the result to the…
A password is a single factor. It is something you know. If an attacker learns it — through phishing, credential stuffing, or a data breach — they have everything they need to log in. Multi-factor authentication (MFA) changes the equation. It requires two or more different types of proof before granting access. A stolen password…
Encryption is the process of transforming readable data (plaintext) into unreadable data (ciphertext) so that only authorized parties can recover the original message. Every encryption system relies on a key — a piece of secret information that controls the transformation. The two fundamental categories of encryption are defined by how that key is used. Symmetric…