DSST Computing and IT flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Cache memory

Small, fast memory between CPU and RAM holding recently used data. It reduces average access time by exploiting locality of reference, but has far less capacity than main memory.

DMA transfer

Direct Memory Access lets a device controller move data blocks to or from memory without the CPU handling each byte, freeing the processor for other work.

RAID 5

Disk striping with distributed parity across at least three drives. It survives one drive failure and improves read performance, but rebuilds are slow and costly.

Copyleft license

An open-source license such as the GPL that requires derivative works distributed to others to carry the same license terms, keeping the source open.

Concurrent license

A software license limiting how many users may run the product at the same time, regardless of how many people have it installed.

Compiler versus interpreter

A compiler translates the whole source program to machine code before execution; an interpreter executes statements one at a time at runtime, trading speed for portability.

Waterfall model

A sequential development life cycle moving through requirements, design, implementation, testing, deployment, and maintenance, where returning to an earlier phase is costly.

Scrum sprint

A fixed-length iteration, commonly one to four weeks, in which a development team builds a potentially shippable product increment from the sprint backlog.

Spiral model

An iterative life cycle that repeats planning, risk analysis, engineering, and evaluation loops, emphasizing risk reduction for large or uncertain projects.

V-model testing

A life cycle pairing each development stage with a matching test level: requirements with acceptance testing, design with system testing, and code with unit testing.

Third normal form

A table is in 3NF when it is in 2NF and no non-key attribute depends transitively on the primary key; this removes redundancy that causes update anomalies.

ACID properties

Transaction guarantees: atomicity (all or nothing), consistency (valid states only), isolation (concurrent transactions do not interfere), and durability (committed changes survive failure).

Differential backup

A backup copying all files changed since the last full backup. Restoring needs the last full plus the latest differential, making restores simpler than incremental chains.

Foreign key

A column or set of columns whose values must match a primary key in another table, enforcing referential integrity between related records.

TCP versus UDP

TCP is connection-oriented with acknowledgments, ordering, and retransmission; UDP is connectionless and best-effort, suited to streaming, voice, and DNS queries.

Private IPv4 ranges

Address blocks 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 are reserved for internal networks, are not routed on the public Internet, and need NAT to reach it.

DNS function

The Domain Name System resolves human-readable hostnames into IP addresses through a distributed hierarchy of name servers, so users need not memorize numeric addresses.

Bandwidth versus throughput

Bandwidth is the maximum capacity of a link in bits per second; throughput is the actual achieved rate, which is at or below bandwidth because of overhead and contention.

Pseudonymization

Replacing direct identifiers with artificial keys so data can still be linked across records without revealing identity; it reduces risk but is not full anonymization.

Data minimization

A privacy principle requiring collection and retention of only personal data that is necessary for a stated purpose, limiting exposure if a breach occurs.

Breach notification duty

The legal obligation to inform regulators and affected individuals within a set period after personal data is compromised, with details of the incident and remediation.

Trade secret

Confidential business information such as an algorithm or formula that gains legal protection without registration for as long as secrecy is maintained.

Patent requirements

An invention must be novel, non-obvious, and useful to be patentable; the grant gives a limited-term exclusive right in exchange for public disclosure.

Fair use factors

A defense weighing purpose of use, nature of the work, amount used, and effect on the market; it is evaluated case by case, not a fixed exemption.

Work made for hire

A doctrine under which copyright in work created by an employee within the scope of employment belongs to the employer rather than the individual creator.

Net neutrality

A regulatory principle that Internet providers treat all lawful traffic equally, without blocking, throttling, or charging for prioritized delivery.

Universal service obligation

A policy requiring telecommunications providers to fund or provide affordable basic service, often in rural or high-cost areas, schools, and libraries.

Unlicensed spectrum

Radio frequency bands open to anyone meeting power and equipment rules, used by Wi-Fi and Bluetooth; devices must tolerate interference and not cause harmful interference.

Cramming and slamming

Two prohibited carrier practices: cramming adds unauthorized charges to a customer's bill; slamming switches a customer's service provider without consent.

Acceptable use policy

An organizational rule set defining permitted and prohibited use of its network and devices, covering unauthorized access, disruptive traffic, and privacy expectations.

Turing Test

A behavioral test of machine intelligence: a human interrogator exchanges messages and cannot reliably tell whether the responses come from a machine or a person.

Forward chaining

An inference strategy in rule-based expert systems that starts from known facts and applies rules repeatedly to derive new conclusions until a goal is reached.