Parallel lines are defined by the same slope and will never intersect. They continue without touching eachother assuming them on the same plane.
Lines are represented by the following expression:
[tex]\begin{gathered} y=mx+b \\ \text{where,} \\ m=\text{slope} \\ b=y-\text{intercept} \end{gathered}[/tex]Then, for a parallel line to:
[tex]y=3x-4[/tex]The slope would be 3.