About crm, powerapps and c#

Web Api & C# What REST stands for? Difference between Put and Patch? Difference between Implicit Conversion and Explicit Conversion? Define MVC? Boxing vs Unboxing? Filters in Aspnet Core? --Angular What is Pipes in angular? if you have two components how to respond to a click event to hide the other component? how to show different text based on localization how to show the maintenance page?