It has a radius, a diameter, and a chord.

What you're describing are elements or features of a circle. Here are explanations of each:

1. Radius: The radius of a circle is the distance from the center of the circle to any point on the circumference (the outer boundary of the circle). The radius is typically denoted as "r". Every point on the circumference is equidistant from the center, which is why all radii of the same circle have the same length.

2. Diameter: The diameter of a circle is the longest distance from one point on the circumference to another, passing through the center. Essentially, the diameter is twice the length of the radius (diameter = 2 * radius). It's denoted as "d".

3. Chord: A chord of a circle is a straight line segment whose endpoints both lie on the circumference of the circle. The diameter is a special case of a chord; it's the longest possible chord you can draw in a circle since it passes through the center.