Computer Memory and Storage

FMD stands for Fluorescent Multi-Layer Disc, an optical disc technology that uses multiple fluorescent layers to store data, allowing much higher storage capacity than traditional DVDs or CDs. Each layer can be read independently without interference from other layers, enabling terabytes of storage on a single disc. The options FastEthernet Measuring Device, Flashing Media Diode, and Flash Media Drive are incorrect expansions.

Computer memory hierarchy by speed (fastest to slowest): Registers → Cache → Main memory → Magnetic disk → Magnetic tape. Access latency increases in this order. Registers are fastest (nanoseconds), while magnetic tape is slowest (minutes to hours).

Gmail started with 1 GB of storage in 2004, which was revolutionary at the time. Google gradually increased storage over the years - first to 2 GB, then beyond. The 2.7 GB figure represents a specific point in Gmail's storage evolution timeline as the company continuously expanded storage capacity.

DDR SDRAM stands for Double Data Rate Synchronous Dynamic Random Access Memory. DDR means it transfers data on both the rising and falling edges of the clock signal, effectively doubling the data transfer rate compared to single data rate memory.

A 32-bit CPU can address 2^32 bytes of memory, which equals 4,294,967,296 bytes or exactly 4096 MB (4 GB). This is a fundamental limit of 32-bit architecture. The incorrect options (4024MB, 4000MB, 4128MB) are all close but not the correct mathematical value. This is why 32-bit systems cannot utilize more than 4GB of RAM.

RAM (Random Access Memory) allows data to be accessed in constant time regardless of physical location - any memory cell can be accessed directly. CPU processes instructions, ROM is read-only memory, and NIC handles network connections.

In C++, the 'new' keyword is the standard operator for dynamic memory allocation. While malloc and calloc are C functions that can be used in C++, 'new' is the preferred C++ approach because it calls constructors and is type-safe. 'dalloc' is not a standard memory allocation function in C or C++.

On a disk surface, a track is a circular path where data is written. Tracks are concentric circles on the disk platter. Each track is further divided into sectors. A cylinder refers to the set of tracks at the same position on multiple disk surfaces (platters).

When optical media like CDs and DVDs are closed (finalized), they become read-only and cannot be modified or written to again. This makes them immune to virus infection after finalization, provided no infected files were already on them when burned. This is a key advantage of optical media for long-term backups.

DPI stands for Dots Per Inch, a measure of spatial printing or video dot density in digital imaging. It indicates how many individual dots can be placed in a one-inch line.

RAID stands for Redundant Array of Inexpensive Disks, a technology that combines multiple disk drives for improved performance, reliability, and fault tolerance in data storage.

USB stands for Universal Serial Bus, an industry standard for cables, connectors, and communication protocols that connect computers to peripheral devices like keyboards, mice, and storage drives.

NFS stands for Network File System, a distributed file system protocol that allows a user on a client computer to access files over a network much like local storage. It's a fundamental protocol in Unix/Linux networking.