Notes:

Unity Component Menu :

Add... (Ctrl+Shift+A):

Mesh:
Effects:
Physics:
Physics 2D:
Navigation:
Audio:
Video:
Rendering:
Layout:
Miscellaneous:
Analytics:
Scripts:
Event:
Network:
UI:
AR:

Components menu commands:

Add... (Ctrl+Shift+A):
Add command allows us to add components to a selected game object in the inspector.

Mesh:
Mesh command allows us to add mesh related components like Mesh Filter, Mesh Renderer, Text Mesh, Skinned Mesh Renderer, etc.

Effects:
Effects command allows us to add effects related components like Particle System, Particle Renderer, Trail Renderer, Line Renderer, Lens Flare, Halo, Projector, Animator, etc.

Physics:
Physics command allows us to add 3D physics related components like Rigid Body, various Colliders, Joints, Cloth etc.

Physics 2D:
Physics 2D command allows us to add 2D physics related components like Rigid Body2D, various Colliders, Joints, etc.

Navigation:
Navigation command allows us to add navigation related components like Nav Mesh Obstacles, Nav Mesh Agent, etc.

Audio:
Audio command allows us to add audio related components like Audio Source, Audio Listener, Audio Reverb Zone, and other Audio Filters.

Video:
Video command allows us to add video player component.

Rendering:
Rendering command allows us to add rendering related components like Sprite Renderer, Light, Canvas Renderer, Camera, Skybox, Flare Layer etc.

Layout:
Layout command allows us to add layout related components like RectTransform, Canvas, and other Groups and Filters.

Miscellaneous:
Miscellaneous command allows us to add miscellaneous components like Animator, Animation, Terrain, Wind Zone etc.

Analytics:
Analytics command allows us to add analytics tracker component.

Scripts:
Scripts command allows us to add behavioral scripts.

Event:
Event command allows us to add event related components like Event System, Event Trigger, various Ray Casters and Input Modules for different platforms.

Network:
Network command allows us to add network related commands like Network HUD, Manager, Animator, Discovery, Start position, etc.

UI:
UI command allows us to add UI related components like Text, Image, Input Field, Button, Toggle Button, etc.

AR:
AR command allows us to add Augmented Reality related components like Spatial Mapping Renderer, Spatial Mapping Collider etc.

Components:
- Components define a game object & its functionality (behavior)
Ex:
Transform:
Defines the position, rotation & scale of a game object
Every game object contains one irremovable component i.e. Transform
Mesh Filter:
Mesh Filter defines the geometry (Mesh) of a game object
Mesh Renderer:
Mesh Renderer renders the geometry (Mesh) based on the Mesh Filter
Collider:
Defines the geometry for physics collision for a game object
Light:
Defines how the light is emitted through a game object
Note: To build any game object the base game object is the empty game object.

Working with components:

Adding Components:
Component Menu – Add a respective component from the list
or
Use Add component button in the inspector

Removing Components:
Click on the gear icon of the component - Remove component

Resetting Components:
Click on the gear icon of the component - Reset
Sets values of a component properties to default values

Moving Components:
Right click on the component name – Move up / Move Down

Copying component values:
Click on the gear icon of the component - Copy component

Pasting component values:
Click on the gear icon of the component - Paste component values

Reset position, rotation & scale:
Click on the gear icon of the component - Reset position/rotation/scale