Before we jump into the Solidity language structure, we need to know what a pragma keyword is and what it means.
Unlike the Objective-C #pragma and Swift MARK, the' pragma' keyword in Solidity describes what version of the compiler should use. Keep in mind that it instructs the compiler to check if the versions do match. It does not turn on or off any language features.
For instance, if we would like to tell the Solidity compiler that we want to use the 0.8.x version, we can start the source file like this: