what has been mentioned above is quite correct..marketing means..think of the product to serve the market..strategize the whole thing..decide the marketing mix..work on the distribution channel etc..marketing in fact is right from conceptualisation of the product, the market and all other aspects of marketing to its final sale
sales is limited to just the converting the finished product into revenue and in some cases with providing service to the users..
However a very important differentiator between marketing and sales is that the goals of the marketing and the sales team are usually different (though in reality they should be aligned).. Marketing focusses on efficiency (getting maximum revenue at minimum cost).. sales focusses on effectiveness (maximum output)