OK POST key terms

A diagnostic routine run by firmware immediately after a computer is powered on, checking core hardware such as CPU, memory, and video before handing control to the boot loader.

Low-level software stored in non-volatile memory on a device that controls its most basic hardware operations and starts the boot process, typically updatable but rarely changed.

Legacy firmware interface on IBM-compatible PCs that initializes hardware, runs the POST, and provides basic runtime services to the operating system through interrupt calls and fixed data structures.

Modern replacement for legacy BIOS that defines a firmware interface with drivers, a boot manager, and support for large disks, secure boot, and pre-boot applications.

Small battery-backed memory area on a motherboard that retains basic configuration settings such as date, time, and boot order when the system is powered off.

The ordered series of steps a computer performs from power-on through firmware initialization, device detection, and loading of the operating system from a selected boot device.

A small program that runs after firmware initialization and loads the operating system kernel or a boot menu into memory so the system can start.

A pattern of audible beeps produced by firmware when the POST detects a fault before video output is available, with meaning defined by the motherboard or BIOS vendor.

A diagnostic adapter inserted into a motherboard expansion slot that displays hexadecimal POST progress codes, helping technicians locate the failing stage when the system will not boot.

The component that converts AC mains power into regulated DC voltages required by the motherboard and internal devices, rated by total wattage and connector types.

A separate regulated DC output channel within a power supply, such as +12 V or +5 V, each with its own current limit that must be respected when connecting components.

A handheld device that connects to power supply connectors and measures output voltages under a small load, indicating whether each rail is within tolerance.

A test instrument that measures voltage, resistance, and continuity, commonly used to verify power output, check fuses, and trace electrical faults on hardware.

The sudden transfer of static electricity between objects at different potentials, capable of destroying or degrading sensitive electronic components if not controlled.

A conductive band worn on the wrist and connected to a grounded point, equalizing the wearer's potential with the equipment to prevent electrostatic discharge damage.

A grounded, dissipative work surface that safely bleeds static charge away from components placed on it and provides a common ground point for wrist straps.

A safety procedure that isolates hazardous energy sources, applies a physical lock, and attaches a warning tag so equipment cannot be re-energized during service.

Wearable gear such as safety glasses, gloves, and hearing protection that reduces a technician's exposure to hazards while performing installation, maintenance, or repair work.

A structured process of identifying hazards, estimating the likelihood and severity of harm, and deciding which controls to apply before starting a task.

The first sector of a partitioned storage device that holds boot code and a partition table limited to four primary partitions and disks up to two terabytes.

A modern partitioning scheme that stores partition entries with globally unique identifiers, supports many partitions and very large disks, and works with UEFI firmware.

A UEFI feature that verifies digital signatures of boot components against trusted keys, blocking unauthorized or tampered code from loading before the operating system starts.

Software that lets the operating system communicate with a specific hardware device by translating generic commands into the device's required control instructions.

A vendor-published catalog of hardware models and components verified to work with a particular operating system or platform version.

A repeatable sequence of steps such as gathering information, identifying the problem, forming and testing a hypothesis, implementing a fix, and documenting the outcome.

A structured investigation that moves beyond the visible symptom to find the underlying reason a fault occurred, so it can be corrected and prevented from recurring.

A controlled process for requesting, reviewing, approving, scheduling, and recording modifications to systems, reducing the risk of unplanned outages and undocumented configuration drift.

A documented, approved set of settings and component versions that represents the known-good state of a system and serves as the reference for comparison and rollback.

A maintained record of hardware, software, and related items with identifiers, owners, locations, and status, used for support, licensing, and security decisions.

A contract or internal agreement defining expected service levels such as response time, resolution time, and availability, along with the consequences of missing them.

An unplanned interruption or degradation of a service that requires a response, distinct from a request for routine help or a planned change.

The defined route and criteria for passing an issue to a higher support tier or specialist when it exceeds the current tier's authority, skill, or time targets.

Rules specifying how long different categories of records must be kept, where they are stored, and when and how they must be securely destroyed.

Documentation recording who handled a piece of evidence, when, and for what purpose, preserving its integrity for investigations or legal proceedings.

The practice of ensuring installed software and media are covered by valid, correctly counted licenses and used within the terms the vendor permits.

A document stating what employees may and may not do with organizational systems, data, and network resources, and the consequences of violations.

A software-defined computer that runs its own operating system on emulated or virtualized hardware provided by a hypervisor on a physical host.

Software or firmware that creates and runs virtual machines, allocating physical CPU, memory, storage, and network resources among them.

A point-in-time record of a system or virtual machine state used for rollback after a failed change, typically not a substitute for a full backup.