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Binary is base 2, so each digit position holds one of exactly two symbols, 0 or 1. Other bases use more symbols, which is why the number of available digits differs between notational systems.
A Boolean type stores a logical state that is either true or false, which is enough to drive conditional logic in a program. Numeric and textual types hold content of a different nature.
A byte is defined as 8 bits, and larger storage units such as kilobytes and megabytes are built from bytes. Smaller and larger groupings exist but carry different names.
The central processing unit executes instructions and performs arithmetic and logical comparisons, making it the processing stage of the input-process-output-storage cycle. The other components support that work rather than perform it.
RAM is volatile memory, so its contents are cleared when power is lost, which is why open work must be saved to storage. Persistent media such as an SSD or hard disk retain data without power.
An input device sends data from the outside world into the computer, and a microphone captures sound for the system to process. Output devices instead present processed data back to the user.
Software as a Service delivers a finished application over the internet while the provider handles servers, patching, and maintenance. The customer simply uses the software through a client such as a browser.
A hypervisor, also called a virtual machine monitor, allocates the host's CPU, memory, and storage to guest virtual machines and keeps them isolated from one another. The other components serve a single operating system or its development tools.
Each binary position is a power of two, so 1011 equals 8 + 0 + 2 + 1 = 11. Reading the same digits in another base would produce a different result.
Hexadecimal is base 16, and 16 equals 2 raised to the fourth power, so each hexadecimal digit stands for exactly four bits, a grouping sometimes called a nibble. This relationship is what makes hexadecimal a compact way to write binary strings.
Hexadecimal is a compact, human-readable shorthand in which each character encodes exactly four bits, so a 48-bit MAC address fits in 12 characters instead of 48. The underlying bits are unchanged by the choice of notation.
A floating-point type is designed to hold numbers that include a fractional part, such as 3.75. The other types either store whole numbers only or cannot represent numeric magnitude at all.
An array stores multiple elements of the same type in a defined order, and each element is reached through its index. That indexing is what separates an array from a lone variable or a flag.
The prefix giga- means one billion, so 3.2 GHz means 3.2 billion cycles per second. The same rule scales the other prefixes: kilo- is a thousand, mega- a million, and tera- a trillion.
Server consolidation lets many virtual machines share the CPU, memory, and storage of a single physical host, which raises utilization and lowers cost and power consumption. Each guest still behaves like a complete computer with its own operating system and network stack.
Infrastructure as a Service provides raw compute, storage, and networking that the customer configures, including the choice and maintenance of the guest operating system. Higher-level models keep the operating system under the provider's control.
IoT devices that measure conditions and report them are sensors, feeding data to a platform for storage and analysis. Actuators instead carry out a physical action after receiving a command.
Data are unprocessed facts and figures, while information is the result of organizing and interpreting that data so it can support a decision. The distinction rests on processing and context rather than on storage location or protection.
An API is a defined set of rules and function calls that lets one program use the features or data of another without knowing its internal workings. It governs interactions between software components rather than file protection, translation, or addressing.
Machine learning builds a model from examples so that patterns are inferred from data rather than written out as explicit rules. A larger, representative training set usually improves accuracy until the gains level off.
Octal is base 8, so the left digit is multiplied by 8: 1 times 8 plus 7 equals 15. Reading the same digits in another base would give a different value.
Splitting the byte into two nibbles gives 1100 and 1010, which equal C (12) and A (10) in hexadecimal, so the byte is written 0xCA. Reversing the nibbles or misreading one of them produces the other values.
Throughput is quoted in bits per second, and a byte contains 8 bits, so 100 megabits per second divided by 8 equals about 12.5 megabytes per second. The metric prefixes for bits and bytes have the same magnitude, so only the division by 8 is needed.
With n bits there are 2 raised to the n unique patterns, so 4 bits give 16 values ranging from 0000 through 1111. Four bits form a nibble, which is half of a byte.
Unicode assigns a code point to characters from essentially every writing system plus symbols and emoji, and encodings such as UTF-8 store those code points compactly. Legacy encodings cover only narrow character sets and cannot represent the full range.
Lossless compression reduces file size while preserving all original data, so every file can be restored exactly. Lossy compression permanently discards some detail and cannot guarantee byte-for-byte recovery. Hashing and encryption serve other purposes and do not provide compression for later exact restoration.
RAID 1 mirrors identical data onto a pair of drives, so two drives is the minimum. Every write is duplicated, and usable capacity equals the size of a single member drive.
A private cloud is dedicated to a single organization, whether it is run on-premises or by a hosting provider. Public clouds pool resources for many unrelated tenants, while community and hybrid models involve broader sharing or a mix of environments.
A Type 1 (bare-metal) hypervisor installs on the hardware itself and manages guest machines without a host OS in between. Type 2 hypervisors are installed as applications on top of a conventional operating system.
DHCP dynamically leases IP addresses plus options such as subnet mask, default gateway and DNS servers to clients. Name resolution belongs to DNS, and time synchronization is normally handled by NTP.
HTTPS is HTTP carried over TLS and defaults to TCP 443. Port 80 is plain HTTP, port 22 carries SSH, and port 3389 is the default for RDP.
An incremental backup captures everything modified since the last backup of any kind, making each run small but requiring the full plus every increment to restore. A differential backup instead captures changes since the last full backup only.
A UPS provides battery-backed power so equipment rides through brief outages and can shut down cleanly during longer ones. Rectification from AC to DC is performed by the server's own power supply units.
Structured cabling standards limit a horizontal twisted-pair copper channel to 100 meters, typically 90 m of permanent link plus 10 m of patch cords. Longer runs require fiber or an intermediate device.
A trunk port tags frames from multiple VLANs, typically with 802.1Q, so they can cross a link between switches or reach a router. An access port belongs to a single VLAN and sends untagged frames to an end device.
A /26 leaves six host bits, which yields 2^6 = 64 addresses. Subtracting the network and broadcast addresses leaves 62 assignable hosts.
Round robin cycles through the server pool in sequence regardless of current load. Least-connections and response-time algorithms instead choose a server based on real-time state.
An AAAA record resolves a name to a 128-bit IPv6 address, while an A record resolves to IPv4. PTR records support reverse lookups and CNAME records alias one name to another.
Containers share the host operating system kernel and package only the application and its dependencies, so they start quickly and consume less memory and disk. Virtual machines each run a complete guest OS, which improves isolation but adds overhead.
A stateful firewall keeps a session table and allows replies belonging to an established, permitted connection. Stateless packet filters require explicit rules for each direction of traffic.
NFS exports a directory tree that clients mount as file-level storage over TCP/IP. iSCSI, FCoE and Fibre Channel present block devices, so the client sees a raw disk instead of shared files.
SNMP runs agents on devices that a manager queries for object identifiers, typically over UDP 161, while traps are sent to UDP 162. Syslog ships event messages and NetFlow exports flow metadata.
The RPO defines how far back the last good copy may be, expressed as a period of time, and therefore how much data loss is tolerable. Maximum allowable downtime is the recovery time objective instead.
Infrastructure as code describes desired infrastructure in machine-readable templates that a tool applies repeatably, providing version history and consistent rebuilds. Continuous integration is about automatically building and testing application code.
WPA3 uses Simultaneous Authentication of Equals to resist offline dictionary attacks against the passphrase and is the successor to WPA2. WEP and the original WPA are deprecated and easily broken.
LC connectors are the small form-factor standard for fiber ports on switches and patch panels. RJ11, BNC and F-type are copper connectors used for telephony, legacy networks and coaxial video.
The four /24 networks cover third-octet values 4 through 7, a contiguous block of four; combining four prefixes removes two bits, turning /24 into /22. The resulting 10.1.4.0/22 spans exactly 10.1.4.0 to 10.1.7.255.
RAID 6 reserves the equivalent of two drives for double parity, so usable capacity is (6 - 2) x 4 TB = 16 TB. This layout tolerates two simultaneous drive failures.
Spanning Tree Protocol elects a root bridge and blocks redundant ports so frames cannot circulate indefinitely around a looped topology. LACP bundles links and VRRP provides a redundant default gateway.
Synchronous replication acknowledges a write only after both copies are committed, so a surviving zone holds every acknowledged transaction. Asynchronous replication and backups both leave a window in which recent writes can be lost.