LaTeX (pronounced LAH-tekh or LAY-tekh) is the de facto standard software to write technical and scientific reports containing mathematical equations or programming code.
With Overleaf, you can use LaTeX to produce high-quality written work that looks better than anything produced in Word. It also helps you keep track of references to equation numbers, bibliographies, and tables of contents automatically. It can handle graphics too.
These are a series of webinars from Overleaf which guide you through its many features.