Eq Pedal - changes the sound by boosting or cutting different Freq.. So by right if you boost everything at the same time.. you get a boosty pedal.
But often Boost Pedals may also have a bit of clipping towards the end so you'll get an overdriven tone as well (or not) .. and if they have tone controls, they would be set up to tweak the right Freq.
Bottom line.. EQ - probably more versatile in terms of shaping tone. Boost Pedal - if non-transparent, will probably make it sound better (to the taste of the builder) if transparent, then it shouldn't change your sound much.