Alibaba Cloud Associate (ACA) Computing [Practice Tests]

A security risk assessment identifies the threats to an organisation's assets, estimates how likely each is and how much harm it would do, and ranks them so that limited effort goes where it reduces the most harm.

Zero trust is a security model in which no request is trusted because of where it comes from, so every access to a resource is authenticated, authorised and checked against policy each time.

Encryption transforms readable data into ciphertext with a key so that only someone holding the right key can turn it back, protecting the data while it is stored or in transit.

A wireless LAN connects devices to a network over radio using the 802.11 family of standards, through access points that bridge the wireless medium onto the wired network and enforce the authentication and encryption that the shared airwaves demand.

TCP/IP is the family of protocols on which the internet runs: IP moves packets between addresses without guarantees, and TCP or UDP ride on top to deliver either a reliable ordered stream or fast unordered messages.

The OSI model is a seven-layer reference framework that separates networking into physical transmission, link, network, transport, session, presentation and application concerns, used to reason about where a problem sits rather than to describe any real protocol stack.

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.

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.

DNS is the distributed lookup system that turns a hostname such as getting-digital.net into the IP address a browser can connect to, by walking a chain of nameservers whose answers are then cached for a lifetime the domain's owner publishes.