No. A subclass is class which inherits a method or methods from a superclass. like:
class Car{
}
class HybridCar extends Car {
}
HybridCar is a subclass of Car.
innerclass is a class defined inside another class. they are a type of "nested classes"
class OuterClass {
...
class NestedClass {
...
}
}
read
here for a better definition.