GameObject

A GameObject is a fundamental entity used to represent objects within a scene in Unity. It acts as a container for components that define an object’s data and behavior. Every GameObject has a Transform component by default, which stores its position, rotation, and scale in the world or hierarchy. To give a GameObject functionality, developers attach components such as scripts, renderers, colliders, rigidbodies, lights, audio sources, cameras, and particle systems.

GameObjects are organized in a hierarchical structure. They can have parent-child relationships, where children inherit their transform from the parent. This hierarchy allows grouping, combined transformations, and structured scene composition. Deactivating a parent GameObject also disables all its children.

The behavior of a GameObject is defined by its components. In Unity, scripting typically relies on lifecycle methods such as Awake, OnEnable, Start, Update, FixedUpdate, LateUpdate, and OnDestroy to initialize, perform per-frame work, and handle teardown. Components communicate through references, events, or messaging, and common interaction patterns include GetComponent and public fields.

Prefabs are reusable templates created from GameObjects or hierarchies. A prefab can be instantiated at runtime to create new instances that share the same structure and components. Modifying the prefab can propagate changes to instances, while per-instance overrides allow customization.

GameObjects can be identified and managed using tags and layers, and their data is serialized as part of scenes and assets. Best practices emphasize modular component design, avoiding unnecessary activity by disabling or removing unused objects, and profiling performance to ensure efficient scene management.