Scrum Product Owner (PSPO l) | Incl. 200+ Prep. Questions

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 hash function turns input of any size into a fixed-size fingerprint in a way that cannot be reversed, so that the fingerprint can verify data or store a password without holding the original.

A public key infrastructure is the system of certificates, certificate authorities and revocation mechanisms that lets a party verify which identity a public key belongs to before trusting it.

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.

IP addressing is the scheme that gives every interface on a network a numeric address, with IPv4's four-byte addresses now supplemented by IPv6's much larger space, and with private ranges reserved for use inside networks that reach the internet through translation.

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.

PaaS is a hosting layer that takes your source code and turns it into a running application for you, owning the machines, the runtime, the build, the routing, the certificates and the restarts, so that shipping becomes a push rather than a project.

Serverless computing runs your code only while an event is calling it: the provider conjures an execution environment on demand, throws it away afterwards, and charges for work performed instead of for capacity sitting idle.

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.

Cloud hosting is the model in which servers, storage and databases are created on demand through an API from a provider's pooled hardware and billed for the time they exist, rather than rented as a fixed box by the month.

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.