There isn't a fixed number of tectonic plates. Instead, it's a dynamic system where the number can change over time. Here's why:

* Continuously Moving: Tectonic plates are constantly moving, colliding, separating, and sliding past each other.

* Plate Boundaries: Where these plates interact, we find major geological features like mountain ranges, volcanoes, and earthquakes.

* Subduction: One plate can dive under another (subduction) which can change the size and number of plates over very long periods.

Major Plates:

We usually talk about 7 or 8 major tectonic plates:

* African Plate

* Antarctic Plate

* Eurasian Plate

* Indo-Australian Plate

* North American Plate

* Pacific Plate

* South American Plate

Smaller Plates:

There are also numerous smaller plates, sometimes called "microplates", that exist alongside the major ones.

Constantly Evolving:

The Earth's tectonic system is a very complex and dynamic process. The number of plates and their boundaries are always shifting and evolving over geological time scales.