What is Real Ale?
Real Ale is beer which contains yeast, is unfiltered and unpasteurised and has finished its fermentation in the cask, Cask Conditioning, also the Campaign for Real Ale have been championing Real Ale since the 1970’s.
The Wikipedia link – http://en.wikipedia.org/wiki/Cask_ale

What is Craft Beer?
Craft beer is beer, all beer made by small brewers could be considered as Craft Beer as there is a large element of hard work and Hand-Crafting to bring beer to glass. If you require a bigger distinction of Craft maybe you could consider that these beers could have more ingredients in them, more malt, more hops, longer maturation and more beer-specific packaging (Cask, Keg or bottle to best suit the style of beer). Other terminology you may want to consider are ‘Artisan Beer’ & ‘Boutique Beer’ though the latter I feel to be pretty obnoxious it may refer to some of the European imported beers best.
Further, I believe a ‘Craft Brewery’ in the public’s eyes is defined by the public and reflected back toward the brewer, the brewer’s beers, design and marketing play a roll in this ethos.
Why can this so-called ‘Craft beer’ cost more for a pint?
More ingredients, longer maturation and different packaging  means it costs more to produce stronger fuller-flavoured beer than it does, say, a pint of your usual ale down the pub. You can brew a low abv beer with light hopping and a fast turnaround and make a profit selling it fairly cheaply to pubs, to make a similar return on stronger heavily hopped beer the price must go up to cover the cost of ingredients and the extra time it may have spent in the fermentation vessel being dry hopped and temperature controlled, and not forgetting the Beer Duty increases the higher the abv, its common sense that if you make a product to sell it must earn you a living otherwise its just a hobby!
Craft & Keg are not the same, putting beer into kegs means you have the additional costs of the Keg, Carbonation, cleaning, filling time etc.