Those functions are intended to solve different problems in .NET that can easilly be solved from X++:
Axapta.ExecuteStmt
is the way to send some SQL (on the X++ internal SQL syntax) to the database that can be a select, update_recordset, etc. Exactly the same functionallity and results that if you write SQL commands inside the X++ code.AxaptaRecord.Call
is a class method. That way, with this function you can only run record methods coded in X++ inside a table (those that can be found inside the Methods node on the AOT, like the usual .find() method).
EDIT: There is a third interesting method:
Axapta.CallStaticClassMethod
is the way to execute an static method saved on a class. As the method needs to be static, you don't pass an object to the function, but just the class name and method name, as it is executed on a new context.