First let's make the two equations in the same form so we can compare them. Let's do that by dividing the first equation by 2 to make it become y = 8x - 1.
We now have two equations:
y = 8x - 1
y = 8x - 1
Since both are the same equation, there will be infinitely many solutions because any value of x will result in the same value of y for both equations.
You can also think of solutions as intersections: if there's one solution then there is one intersection when the equations are graphed. Infinitely many solutions means there are infinitely many intersections when the lines are graphed since they are the same line.