We deliver a motivational introduction to quantum field theory, aimed at curious students interested in that important and broad realm of contemporary physics. Assuming knowledge of the well-known quantum mechanics and special relativity fundamentals, we briefly review and discourse about its main ideas, methods and precepts, looking forward a generalization to quantum field theory. We show how the apparent incompatibility between relativity and quantum mechanics, present in some initial textbooks on the subject, may be elucidated and cleared out through the field concept, allowing for a consistent description of elementary particles interactions in the domains of validity intersection for those two theories. We explain in a clear and simple way what came to be known in the literature as second quantization. The text, eminently didactic and motivational, is accessible to final year undergraduate or starting post graduate students with a good prior knowledge of special relativity and quantum mechanics.