How to Add Product as different varieties like size as mentioned below in picture

Question

I want to add product with three different sizes and whenever the size has been selected it should be active for user.

Anyone help me?

Answer 1

You can Use configurable product for that.

this is the tutorial for creating configurable product http://docs.magento.com/m1/ce/user_guide/catalog/product-configurable.html

and also as you show thumbnail of a simple product you can use Marius extension for simple product thumbnail https://github.com/tzyganu/Switcher

Hope so above two links will help you

Answer 2

Use Configurable Product or simple product with custom option for you need

A configurable product looks like a single product with drop-down lists of options for each variation. Each option is actually a separate simple product with a unique SKU, which makes it possible to track inventory for each product variation. You could achieve a similar effect by using a simple product with custom options, but without the ability to track inventory for each variation.

Check This link for create configurable product.

And

Check This link for create simple product with custom option.