Meta Keyword is the keyword which helps to search according to the particular keyword. It can be can be set while creating the product. From the frontend, you can search with the particular keyword related to the products. This is to be used in HTML language for the search engine optimization(SEO) as the keyword.
Enter some descriptive text for SEO purpose of this product.You can add the description for the product and it will be will be saved as meta description. This is to be used in HTML language for the Search Engine Optimisation(SEO) as the Description.