C# (pronounced C-Sharp) is a multi-paradigm programming language developed by Microsoft Corporation. It is widely used for building Windows desktop applications and games and it's also essential for developing Microsoft apps. It's known for its simplicity and versatility while providing modern language features such as strong type checking, automatic garbage collection, and array bounds. If you're skilled in C#, you can create client applications, database applications, distributed components, and much more.

In the 'Tech Skills' category on the WomenTech Network job portal, having a grounding in C# can open a plethora of opportunities for you in various job roles. Firms often seek candidates who can competently design, code, test and debug programs in C#, making it a highly valuable skill.

Several fundamentals can serve as a strong foundation for learning or mastering C#. Understanding the basic principles of programming, such as variables, control structures, loops, and arrays, can greatly facilitate the learning process. It's also advantageous to grasp principles of Object-Oriented Programming (OOP), such as inheritance, polymorphism, and encapsulation, as C# is a fully object-oriented programming language.

Knowing its parent language, C++, and Java, which shares many similar principles, can aid in understanding C#. In practice, developers often use C# in conjunction with other technologies like .NET Framework, .NET Core, and ASP.NET, so familiarity with these can serve as a stepping stone to mastering C#. Familiarity with SQL (for working with databases) and XML (for working with data formats) could also provide a significant advantage.

Having C# in your 'Tech Skills' portfolio sets the stage for a formidable career path in programming, gaming, app development, and beyond, marking you as a versatile and valued candidate in the technology sector.