No.  Market penetration is the percentage of a market’s potential buyers that have actually bought the product. Market share, on the other hand, is the percentage of a market’s sales that are generated by a particular product.
Typically, market penetration and market share are used interchangeably, but they are not the same thing. Market penetration is a measure of how much of the total potential market a product has captured. e.g. The number of units of a product sold in relation to the total number of units that could be sold.
Market share, on the other hand, is a measure of how much of the market a particular product or company has captured relative to its competition. e.g. The percentage of a market's total spending or revenue that is captured or generated by a particular product or company. In the Digital Marketing industry, Market Penetration could examine who has shipped the greatest proportion of the total number of SEO software licences sold, whilst Market Share might look at who has the greatest proportion of revenues from sales of software, or services, or the greatest slice of organic visibility.