Geometry, stemming from the Greek words “geo” (earth) and “metron” (measure), is a fundamental branch of mathematics. Below is a comprehensive overview covering the key aspects and sub-disciplines of geometry:

### 1. **Foundational Concepts**:

**Points, Lines, and Planes**: The foundational elements upon which all geometric concepts are built.**Angles**: The intersection of two rays or line segments creates angles, which are central to many geometric concepts.

### 2. **Euclidean Geometry**:

**Named after Euclid**, who authored “The Elements,” a seminal work laying out the axiomatic foundations of geometry.- Involves the study of shapes, sizes, properties, and dimensions of objects and spaces in the two- and three-dimensional realms.

### 3. **Non-Euclidean Geometry**:

- Emerged in the 19th century to explore geometric concepts outside the realm of Euclidean postulates.
- Two primary types:
**Hyperbolic and Elliptic**geometry, each with different assumptions about parallel lines.

### 4. **Coordinate Geometry**:

- Combines algebra and geometry, allowing geometric problems to be solved algebraically.
- Incorporates equations to represent geometrical figures like lines, circles, and curves.

### 5. **Differential Geometry**:

- Studies geometry using calculus.
- Looks at curves, surfaces, and manifolds, often in higher-dimensional spaces.

### 6. **Analytic Geometry**:

- Similar to coordinate geometry, but extends to higher dimensions and more complex geometrical forms.

### 7. **Topology**:

- Often referred to as “rubber-sheet geometry”, studies properties of space under continuous transformations.
- Investigates concepts like compactness, connectedness, and convergence.

### 8. **Algebraic Geometry**:

- Studies the solutions of polynomial equations and their geometric properties.
- Bridges algebra and geometry, exploring complex geometrical shapes using algebraic techniques.

### 9. **Computational Geometry**:

- Focuses on the algorithmic aspects of geometric problems.
- Applications include robotics, graphics, GIS (Geographic Information Systems), etc.

### 10. **Practical Applications**:

- Geometry has vast applications across various fields including architecture, engineering, physics, computer science, and art.

### 11. **Historical Evolution**:

- Geometry has evolved significantly over the millennia, from ancient civilizations’ practical geometry to the abstract and more complex modern-day geometrical theories.

### 12. **Key Figures**:

- Besides Euclid, many mathematicians like Pythagoras, Archimedes, Descartes, and Gauss have made significant contributions to geometry.

Geometry is a rich and evolving field of study, tightly interlinked with many other branches of mathematics and science. Through its exploration, we are better able to understand the spatial relations and dimensions of the world around us.