Fields can be altered a bit using the following keywords:

• readonly -> can have its value set only in the constructor. Trying to change its value outside of a constructor will cause a compiler error
• const -> replaced at compile time with their values
• volatile -> indicates that a field might be modified by multiple threads that are executing at the same time

Never used volatile in my life so here's the official docs: https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/volatile