**Q. Define the terms data type and abstract data type. Comment upon the significance of both these. **

**Ans:**

We determine the total amount of memory to reserve by determining the suitable abstract data type group to use and then deciding which abstract data type within the group is correct for the data.

There are four data type groups which are stated as follows:

1. The **Integer **Stores the whole numbers or the signed numbers.

2. The **F****l****oating-point **Stores the real numbers (i.e. fractional value). Ideal for storing bank deposits where pennies (fractions of a dollar) can quickly add up to a few dollars easily.

3. The **Character **Stores a character. It is perfect for storing names of things.

4. The **B****oolean **Stores the true or false value. The right choice for storing a yes or no or simply true or false values response to a question.

**The Abstract Data Types:-**

It is a useful tool which is used for specifying the logical properties of the data type is the abstract data type or ADT. The "abstract data type" refers to the basic mathematical or calculation concept which defines the data type. In defining ADT as a mathematical concept, space or time efficiency does not matter at all.

An ADT is of two parts:-

i) a value definition

ii) an operator definition.

The value of definition defines the collection of values for the ADT and consists of two parts:

i) a definition clause

ii) a condition clause.

The value consist definition for the ADT RATIONAL says that a RATIONAL value comprises of the two integers, the second of which is not equal to 0. Hear we use array notation to point out the parts of an abstract type.