Agile Scrum Master Certification: Scrum Project Management

A penetration test is an authorised, scoped attempt by a skilled tester to exploit weaknesses in a system the way an attacker would, ending in a report the owner can act on.

Incident response is the prepared, practised process by which an organisation detects a security incident, contains it, removes the cause, recovers, and learns from what happened.

Threat modelling is the structured practice of asking what could go wrong with a system, who would make it go wrong and how, while the design can still be changed cheaply.

Subnetting divides an address block into smaller networks by choosing how many leading bits identify the network, written as a prefix length or a subnet mask, so that each subnet has its own range of host addresses and its own routing entry.

Routing is how packets move between networks: each router holds a table of known destinations and the next hop toward each, learned by configuration or by a protocol, and forwards each packet to the most specific match.

Switching is the forwarding of frames within a single network segment by a device that learns which hardware address sits on which port and sends each frame only where it needs to go.

A container is an application packaged together with the libraries and configuration it needs, run as an isolated process on a host that is already switched on, so the same package behaves the same way on a laptop, in a build pipeline and in production.

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.

A web server is the program listening on a network port for HTTP requests and answering them, either by returning a file from disk or by handing the request to application code behind it.

Load balancing is the practice of putting one entry point in front of several interchangeable servers and distributing incoming requests among them by a chosen policy, so that no single machine carries the traffic and no single machine's failure takes the service down.

A CDN is a worldwide network of servers that answers requests for your site from a location near the person asking, instead of sending every request back to the single machine your site runs on.