This is a job title which will only make sense to people who've either worked as one themselves, has worked in a company which requires one, or knows someone who has. If it's a new term on you, then we'll shed some light on it. A technical lead is a highly specialized computer programmer who creates a piece of software and then stays with it rather than moving onto new things. That makes them different from software architects, who will move from one creation to the next.
A technical lead will work on improving the system on an ongoing basis, as well as providing technical support to the people who use it. Think of them as software landlords! You'll need a master's degree in computer science to work in this role, as well as functional knowledge of how to program in all common web and software languages. If you don't already have some experience in those fields, becoming a technical lead might take you a while.