edad, noun:
age

La edad covers two aspects. First, your or someone else’s age:

a mi edad
at my age

Tenemos la misma edad.
We’re the same age.

Notice the use of tener in the previous example. You also use tener and edad to say at what age people do or did something:

¿A qué edad empezó usted a navegar?
At what age did you start sailing?

Edad can also refer to a historical age:

en la Edad Media
in the Middle Ages

en la Edad de Oro
in the Golden Age (of Spanish Literature)