Right now I'm trying to make a map, but don't know which way is the best to do it. In professional MMORPG making, how do programmers represent the game map? I hope it is not just by 1's and 0's inside a text file right? I thought about use a black and white picture, where black = no move (a wall), and white = no friction (walking on road)... grey means it is somewhat slower (for example walking on sand or grass) is this the professional way to do it? or if not, can i take some ideas from everyone? thanks!

I think its better to make some kind of map editor where you can make this kind of modification and save map in supported format.

Professional game developers don't make or store maps in any one particular format. A map file is one of those things that is highly variable and is best suited to being customized specifically for the problem at hand.

To that end, you should design and implement you map file with the same goals in mind: solve the problem as best you can. If all you need to represent in the map is whether or not an area is traversable and the speed at which is can be traversed, then an image like you suggested would be fine.

For what it is worth, however, the map formats used by commericial games tend to be rather more complex than that.

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I think its better to make some kind of map editor where you can make this kind of modification and save map in supported format.

That depends on how complex the map format will ultimately be. If it isn't going to be more than an image (as in the OPs example, or a heightmap) there is precious little reason to waste extra time implementing what is essentially a limited painting program. If the format will be complex, of course, then it is a different story.