ok...i got ur question now
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It all depends on what kind of model you are trying to texture.like some models can be textured easily by just putting on some textures on them and still look realistic and whereas there are some models which require you to unwrap your model and paint you own textures and slap it on..but procedurals are a special kinds,in that they are generated using some mathematical functions.so they are
random in nature and can be animated easily.
Now there are somthings that can be done using both procedurals as well as texture images. in that case you should decide upon the quality you require and the nature of the model(i.e humans, trees, cars, etc...). eg. generally you should prefer textures images for humans although you could do away with some procedurals too.So if you require precise control of you textures over your model you should opt for texture images wrapped onto your models and if you require randomness(or even animate that easily),like water surface,that dont require that precise position of texture over you model you should chose procedurals....
hope this was helpful this time...