Understanding Phase Difference between y1=a. sin(ω.t) and y2=a. sin(ω.t + φ)

[Miraj Kayastha]

There are two waves
y₁=a. sin(ω.t)
&
y₂=a. sin(ω.t + φ)

My question is what is the phase difference of these two waves?

Is it "φ" or "φ/ω"?

 

[Nugatory]

What do you think and why?

 

[Miraj Kayastha]

I think its "φ/ω"

http://www.intmath.com/trigonometric-graphs/3-graphs-sin-cos-phase-shift.php