VMware Cloud Foundation 5.2 Architect Exam VCP-VCF

A firewall is a control that allows or blocks network traffic according to rules about its source, destination, protocol and, in modern forms, its content and the application it belongs to.

A virtual private network carries traffic through an encrypted tunnel over a public network so that a remote device or site behaves as though it were connected to a private one.

An intrusion detection system watches network traffic or host activity for signs of attack and raises alerts, while an intrusion prevention system sits inline and can block what it recognises.

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.

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.

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.

Caching keeps the result of expensive work, such as a rendered page or a database query, and serves that stored copy until it expires, making it the largest single source of speed on any busy website.

Uptime is the proportion of time a service answers requests, quoted in nines, and a service level agreement is the contract clause setting out how that proportion is counted and what the provider owes when it falls short.

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.