Term of the Moment
Enigma
Definition: memory
Random access memory (RAM) is the temporary workspace in a computer, smartphone, tablet, etc. When the device is turned off, the content in memory is lost. The interplay between the CPU, memory and storage is how work gets done in a computer-based device. Memory capacity ranges from 4GB to 32GB (gigabytes) and higher. See dynamic RAM, memory card and storage vs. memory.
It All Takes Place in Memory
All program execution and data processing takes place from memory, often called "main memory." The program's instructions are copied into memory from storage or the network and then extracted into the CPU for analysis and execution. The instructions direct the device to input data into memory, process the data in memory and output the results from memory.
Processing Means Calculate, Compare and Copy
All data are processed (calculated, compared and copied) in memory (see 3 C's). As programs and data are copied into memory, the previous contents of that memory space are lost. After processing, the results are copied from memory to a screen, printer, storage device or the network.
An Electronic Checkerboard
Memory Doesn't Remember
If memory is temporary, why call it memory? Because the first memory "did remember," but today's memory chips do not. However, for special purposes but not the main memory in a computer, there are memory chips that do remember (see non-volatile memory). See storage vs. memory.
Memory Can Be Clobbered!
Memory is allocated by both the operating system and applications but then released when no longer needed. However, errant programs can reserve memory and not let go, reducing the amount for other programs. In addition, bytes are set aside in a program to keep track of things, and if those bytes wind up in memory that becomes corrupted because of bugs in the software, the only solution is to reboot the computer and start over.
It All Takes Place in Memory
All program execution and data processing takes place from memory, often called "main memory." The program's instructions are copied into memory from storage or the network and then extracted into the CPU for analysis and execution. The instructions direct the device to input data into memory, process the data in memory and output the results from memory.
Processing Means Calculate, Compare and Copy
All data are processed (calculated, compared and copied) in memory (see 3 C's). As programs and data are copied into memory, the previous contents of that memory space are lost. After processing, the results are copied from memory to a screen, printer, storage device or the network.
Programs and data reside in disk or solid state storage (SSD) in blocks of several thousand bytes. The blocks are input into memory, which has a separate address for each byte (each square). This single-byte addressability enables the extraction of each instruction in a program for execution and each field in a record for processing. See byte addressable, early memory and RAM.
If memory is temporary, why call it memory? Because the first memory "did remember," but today's memory chips do not. However, for special purposes but not the main memory in a computer, there are memory chips that do remember (see non-volatile memory). See storage vs. memory.
Memory Can Be Clobbered!
Memory is allocated by both the operating system and applications but then released when no longer needed. However, errant programs can reserve memory and not let go, reducing the amount for other programs. In addition, bytes are set aside in a program to keep track of things, and if those bytes wind up in memory that becomes corrupted because of bugs in the software, the only solution is to reboot the computer and start over.