When ties are used to connect eighth notes, an "off the beat" feel is created. This is called syncopation. When a chord change is anticipated by half a beat, it is described as giving the rhythm a push. These things are demonstrated in the following example.
This example uses both rests on the beat and ties on the beat to create syncopation. Notice once again the use of the first finger across the 3rd and 4th strings at the 2nd fret.