Ohjelmakäskyt

Ohjelmakäskyt, often translated as program instructions or commands, are the fundamental units of a computer program. They are specific directives that a processor can understand and execute. These instructions dictate the operations a computer performs, ranging from simple arithmetic calculations to complex data manipulations and control flow decisions.

The set of all possible instructions a particular processor can execute is known as its instruction set. Different processor architectures, like x86 or ARM, have different instruction sets, meaning a program compiled for one architecture will not run on another without recompilation or emulation.

At a low level, ohjelmakäskyt are represented in binary code, but they are typically written by programmers in higher-level programming languages such as C, Python, or Java. Compilers or interpreters then translate these human-readable instructions into the machine code that the processor can directly interpret and execute.

Common types of ohjelmakäskyt include data transfer instructions (moving data between memory and registers), arithmetic and logical instructions (performing calculations and comparisons), control flow instructions (altering the order of execution, such as jumps or branches), and input/output instructions (interacting with external devices). The sequence and combination of these instructions form the logic of a software application, enabling it to perform its intended tasks. Understanding ohjelmakäskyt is crucial for comprehending how software interacts with hardware at the most basic level.