Params

Params, short for parameters, is a broad term used across computing, mathematics, and data science to describe values that influence the behavior or outcome of a system, function, model, or process. In programming, a parameter is a variable defined by a function or method signature, representing data the function needs to operate.

A key distinction is between formal parameters (the variables named in a function definition) and actual parameters or arguments (the values supplied when the function is called). Different languages vary in how values are passed, such as by value or by reference, and whether parameters have defaults or are required. Many languages also support variadic parameters, which accept a variable number of arguments and collect them into a structure like an array or list. For example, C# uses a params keyword to denote a parameter array, Python uses *args for positional arguments, and Java supports varargs with an ellipsis notation.

In web and software interfaces, the term is common in the form of query parameters, appended to URLs after a question mark to convey options or data. These parameters are typically name=value pairs and may be repeated or encoded, depending on the API design.

Outside programming, params appear in mathematics as parameters that define a family of objects, such as parametric equations where the parameter traces a curve. In machine learning, parameters are the learnable components of a model, such as weights, while hyperparameters are set before training and control aspects of the learning process.

Overall, params are a flexible concept used to tailor behavior, configuration, and description across diverse technical domains.