BCCITB flashcards

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

CPU ALU function

The arithmetic logic unit performs integer arithmetic and logical comparisons inside the processor, while the control unit coordinates instruction fetch and execution.

Volatile vs non-volatile memory

Volatile memory such as RAM loses its contents when power is removed. Non-volatile storage such as SSDs and HDDs retains data across power cycles.

RAID 5 usable capacity

RAID 5 stripes data with single distributed parity, survives one drive failure, and provides usable capacity equal to the total of all drives minus one drive.

Binary capacity units

One byte equals eight bits. In binary units one kilobyte is 1024 bytes, one megabyte is 1024 kilobytes, and one gigabyte is 1024 megabytes.

PCIe lane purpose

PCI Express lanes carry high-speed serial data between the motherboard and expansion devices such as graphics cards and NVMe drives, with x16 offering the widest bandwidth.

Kernel mode vs user mode

Kernel mode allows unrestricted hardware access and privileged instructions. User mode is restricted, and applications request services through system calls that transition into the kernel.

Process vs thread

A process has its own isolated address space. Threads within a process share that address space and heap but keep separate stacks and register state.

Virtual memory and thrashing

Virtual memory maps logical addresses to physical frames using page tables. Thrashing occurs when excessive paging consumes most CPU time and throughput collapses.

Linux chmod 755 meaning

Permission 755 grants the owner read, write, and execute; group and others receive read and execute only. Each digit is the sum of rwx values 4, 2, and 1.

FAT32 file size limit

FAT32 cannot store a single file larger than 4 GB, which is why exFAT or NTFS is chosen for large media files and modern drives.

HTTPS default port

HTTPS uses TCP port 443 and encrypts HTTP traffic with TLS, protecting confidentiality and integrity between browser and server.

TCP vs UDP

TCP is connection-oriented with handshakes, sequencing, and retransmission. UDP is connectionless with no delivery guarantee, suiting DNS queries, VoIP, and streaming.

APIPA address meaning

An address in the 169.254.x.x range is self-assigned by the client when no DHCP server responds, indicating a DHCP or link problem.

DNS record types

A records map names to IPv4 addresses, AAAA to IPv6, CNAME creates an alias, MX directs mail, and TXT carries verification or policy text.

Private IPv4 ranges

The private IPv4 ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. They are not routed on the public internet and require NAT for external access.

Switch vs router layer

A switch forwards frames by MAC address at OSI Layer 2. A router forwards packets by IP address at Layer 3 and connects separate networks.

Multi-factor authentication

MFA requires two or more different factor types: something you know, something you have, or something you are. Two passwords do not qualify as MFA.

Symmetric vs asymmetric encryption

Symmetric encryption such as AES uses one shared key and is fast. Asymmetric encryption such as RSA uses a public and private key pair for exchange and signatures.

Hashing purpose

A hash is a one-way fixed-length digest used to verify integrity and store salted passwords. It is not reversible encryption and does not hide data for later decryption.

Worm vs virus

A virus attaches to a host file and needs user action to spread. A worm self-propagates across networks without user interaction or a host file.

Phishing vs spear phishing

Phishing sends broad fraudulent messages to many recipients. Spear phishing is tailored to a specific person or organization using researched details to appear credible.

3-2-1 backup rule

Keep three copies of data, on two different media types, with one copy stored offsite. This protects against device failure, corruption, and site disasters.

Least privilege principle

Users and processes receive only the permissions required for their tasks, limiting damage from mistakes, compromised accounts, and malicious insider activity.

Troubleshooting first step

The first step is to identify and document the problem by gathering symptoms from the user, checking recent changes, and reproducing the issue where possible.

No POST diagnosis

When a machine powers on but shows no display or POST, check power connections, monitor cable, RAM seating, and diagnostic beep codes before replacing components.

DNS lookup command

The nslookup or dig command queries DNS servers to resolve a hostname and reveal the returned records, helping distinguish name resolution from connectivity faults.

Spooler restart fix

A stuck print queue is often cleared by stopping the print spooler service, deleting pending jobs, and restarting the service, then resending the document.

IaaS vs SaaS responsibility

With IaaS the customer manages the operating system and applications. With SaaS the provider manages nearly everything, and the customer manages users, data, and access.

Type 1 hypervisor

A Type 1 hypervisor runs directly on bare-metal hardware, while a Type 2 hypervisor runs as an application on top of a host operating system.

Containers vs virtual machines

Containers share the host operating system kernel and start quickly with low overhead. Virtual machines each run a full guest operating system on a hypervisor.

Serverless computing

Serverless platforms run code on demand without managing servers, scale automatically, and bill per invocation and execution time, with cold starts adding latency.

Incident vs problem

An incident is an unplanned service interruption restored as quickly as possible. A problem is the underlying cause investigated to prevent recurring incidents.

SLA vs OLA

A service level agreement is a commitment to the customer about service levels. An operational level agreement is an internal commitment between supporting teams.