Questions related to any kind of object. (mesh, text, curve, etc.)
The geometry of a scene is constructed from one or more objects. These objects can range from lights to illuminate your scene, basic 2D and 3D shapes to fill it with models, armatures to animate those models, to cameras to take pictures or make video of it all.
Each Blender object type (mesh, light, curve, camera, etc.) is composed from two parts: an Object and Object Data (sometimes abbreviated to “ObData”):
Object - The object is like a "container" or a "box" for object data
- Holds information about the position, rotation and size of a particular element.
- Also holds Modifiers, physics and certain animations.
Object Data - Is like the content of the "box". For example:
- Meshes, curves, surfaces, metas: - Stores geometry (object shape), material list, vertex groups, etc.
- Cameras: - Store focal length, depth of field, sensor size, etc.
- Lights - Light strength, type (spot, point, area, sun) and the associated node tree.
Each object has a link to its associated object-data, and a single object-data may be shared by many objects.
More info at the Blender Manual