.NET Core is a free, open-source platform made by Microsoft for building apps that can run on Windows, Linux, and macOS.

Example: If you make a calculator app with .NET Core, it can run on a Windows laptop, a Mac, or even a Linux computer.

Difference from .NET Framework:

.NET Framework only works on Windows.

.NET Core works on Windows, Linux, and macOS (cross-platform).

.NET Core is newer, faster, and better for modern apps.

Simple Analogy:
.NET Framework is like a charger that only fits one type of socket (Windows).
.NET Core is like a universal charger that works everywhere (Windows, Mac, Linux).