Below is a G Major chord expressed as a chord diagram. Notice there is only one note hit per string.
Notice the play button under the diagrams... Hit them to see and hear and examples of how these diagrams work.
Next we see a G Major scale expressed as a scale diagram. Notice that with scale diagrams you hit more than one note per string.
Chord Progressions are just a series of chords in a particular order. This site is concerned with the order of chords not how they are played. For example, in the progression below I show the chords that are to be used and the order they go in, I don't try and tell you how the chords should be played.