plainObject

A plain object, often referred to as a plain JavaScript object, is a fundamental data structure in JavaScript. It is an object that was created using the object literal syntax, the `new Object()` constructor, or `Object.create(null)`. These objects are characterized by having no special internal behaviors or properties beyond those of a standard JavaScript object. They do not inherit from specific classes or instances of built-in JavaScript types like Array, Date, or RegExp.

The primary purpose of plain objects is to serve as containers for key-value pairs, allowing for the organization and representation of data. Keys are typically strings or Symbols, and values can be any JavaScript data type, including other objects, functions, or primitives. They are widely used for configuration settings, data transfer objects (DTOs), and representing entities with various properties.

In contrast to objects created from class constructors or built-in types, plain objects generally do not have prototype chains that lead to complex built-in functionalities. This makes them predictable and easy to manipulate. For instance, when iterating over a plain object's properties, one is typically dealing with its own enumerable properties or those inherited from `Object.prototype`, unless `Object.create(null)` was used, in which case it has no prototype at all. This simplicity is often leveraged in libraries and frameworks for managing data.