Introduction to Cisco Networking - CCNA Prep

Phishing is an attack that deceives a person into revealing credentials, approving a payment or running malicious content, usually through a message that impersonates someone they trust.

Ransomware is an attack in which criminals gain access to an organisation's systems, encrypt or steal its data, and demand payment to restore access or withhold publication.

A security operations centre is the team, tooling and process that monitors an organisation's systems for security events around the clock, triages alerts, and starts the response to those that are real.

A VLAN divides one physical switched network into several logical segments, each with its own broadcast domain, by tagging frames with a VLAN identifier so that ports and devices in different VLANs cannot reach each other without a router.

Network address translation rewrites the addresses and ports in packets as they cross a network boundary, most commonly so that many devices with private addresses can share one public address to reach the internet.

DHCP is the protocol by which a device joining a network asks for and receives an address, a subnet mask, a default gateway and DNS servers from a server, for a limited lease period, so that nobody has to configure addresses by hand.

Object storage keeps every file as a self-contained object (the bytes, a unique key and some metadata) inside a flat bucket you read and write over HTTP, with no drive to mount and no directory tree underneath it.

Kubernetes is an open-source system that runs containers across a cluster of machines, keeping the number and placement of running copies matched to a declared desired state, and restarting, rescheduling and scaling them without a person intervening.

IaaS is the layer of cloud computing where you rent raw infrastructure through an API, meaning virtual machines, disks and networks, and take responsibility for the operating system and everything you install above it.

Shared hosting puts your website on a machine that is simultaneously running hundreds of other people's, pooling its processor, memory and disk between all of you, which is both why it costs so little and why your speed partly depends on strangers.

A VPS is a software-defined slice of one physical machine that behaves as a server in its own right, with its own operating system, reserved CPU, memory and disk, and administrative access down to the kernel.

A dedicated server is an entire physical computer rented by a single customer, with no hypervisor taking a share and no other tenants on the hardware, chosen when consistent performance, specific components or provable isolation matter more than the ability to resize in seconds.