Inputs

Inputs refer to data, signals, or commands that originate outside a system and are consumed by it to produce results. In computing, inputs are the information a program uses to perform its tasks and decisions, as opposed to outputs, which are the results produced by the program.

Common sources include human input via keyboards, mice, touchscreens, microphones; device sensors such as temperature, light, or accelerometers; network or API inputs; and programmatic inputs like files, environment variables, and command-line arguments.

Input handling covers capture, validation, parsing, and transformation. Validation ensures inputs meet expected formats and ranges; normalization maps variants to a canonical form; parsing interprets structured data; sanitization removes unsafe content to protect against injection attacks.

In software, input may come through standard input (stdin), files, or network streams; in UI design, forms, controls, and event handlers manage user input. In function design, inputs are parameters or arguments. In data processing, inputs are raw data sets; in control systems, inputs are external signals influencing system behavior.

Quality considerations include completeness, accuracy, consistency, timeliness, and integrity. Proper input handling improves reliability, security, and user experience.