what is difference between var and dynamic ,difference between throw and throws

Var - checks datatype compile based on the assignment value.
Ex : var obj = 10;
obj data type will be integer.

Dynamic - datatype of the object is known at runtime.

Throw:
Throw is a keyword which is used to throw an exception explicitly in the program inside a function or inside a block of code.

Throws
Throws is a keyword used in the method signature used to declare an exception which might get thrown by the function while executing the code.

var resolved at comipletime while dynamics is resolved at runtime