Difference in Market Penetration and Market Segmentation?

What is the main difference between market penetration and market segmentation?

Market Penetration—making more sales to present customers without changing product in any way. For example a detergent company reduces a price and sale the product on low profit margin just to penetrate in the market and increase the sale volume. This strategy is known as Market penetration.
Market segmentation is a marketing approach that encompasses the identification of different groups of customers with different needs or responses to marketing activity. For example a Pakistani company, want to sale its product all over the country. But it is very difficult to sale at the same time and keeping the sales records. For making it easy, companies usually divide sales area on the basis or cities and town. This division is known as geographical segmentation, which is type of market segmentation. This segmentation may be geographic, psycho graphic, demographic etc