Watch the Mo' Modal Solo online guitar lesson by Jeff Scheetz from Blues-Rock: Secret Sauce
When we talk about "modes" and "modal soloing" that just means that we're relying on a specific modal scale to solo with.
Just like paint comes in different colors, each modal scale has a unique texture and sound that you can "color" your solos with.
Of course, you don't want to paint every picture using just one color, so likewise you don't want to have every solo sound the same. This is where knowing your modes and a little bit of modal theory comes into play.