Meta tag helps crawler suggest about the category/topic/theme of your website. So that you can appear on specific keywords on search results.For example your site sells electronic products then you will have to put these keywordBuy Shoes OnlineWomen's Footwear OnlineHigh Heels SandalsAnd then the description for example.Buy Women's Footwear, High Heels, Wedges and Flats sandals at the Sole Fry online shop with Free and fast delivery. Find the latest womenâ€™s footwear and casual styles today.So when search engine crawler will read the keywords and description it will put your site under the best category. How to appear on Google's first page is a different story!Hope this help you!!