1. Point of Concurrency
Definition: the point at which two or more lines, line segments or ray intersect. Picture:

2. Incenter
Definition: the point of concurrency for the three angle bisectors.
Picture:

3. Circumcenter
Definition: the point of concurrency for the three perpendicular bisectors. Picture:

4. Orthocenter
Definition: the point of concurrency for the three altitudes. Picture:

5. Inscribed
Definition: Shape that is inside the other shape. Picture: The circle is inscribed.

6. Circumscribed
Definition: Shape that is outside the other shape. Picture: The triangle is circumscribed.