Maestro vs. profesor vs. docente

The Spanish words 'maestro', 'profesor', and 'docente' all translate to the general term 'teacher' in English, yet carry different connotations and usage in various contexts.

Maestro

'Maestro' typically refers to a teacher that specializes in instructing primary (elementary) or infant school students. They generally teach a variety of subjects, as is common in lower grade levels.
El maestro de mi hijo es muy amable.
(My son's teacher is very kind.)
He sido un maestro de escuela primaria durante diez años.
(I have been an elementary school teacher for ten years.)

Profesor

'Profesor', on the other hand, usually refers to the teachers at secondary (high school) and tertiary (college/university) education levels. These are instructors who specialize in one or more particular fields of knowledge, teaching specific subjects rather than a broad curriculum.
Mi profesor de matemáticas en la universidad es muy exigente.
(My university math professor is very demanding.)
La profesora de historia del colegio nos hizo un examen difícil.
(The high school history teacher gave us a difficult exam.)

Docente

'Docente' is a more formal or official term used for any person involved in education at any level. It is commonly used in administrative or professional contexts.
Los docentes de esta institución están altamente capacitados.
(The teachers of this institution are highly trained.)
"El papel del docente es fundamental en el aprendizaje del estudiante" es una frase común en las conferencias educativas.
("The role of the teacher is fundamental in student learning" is a common phrase in educational conferences.)

Summary

In summary, 'maestro' primarily refers to teachers at the primary level, 'profesor' typically refers to teachers at the secondary and tertiary level, while 'docente' acts as a formal or universal term for those involved in education at any level.