Shifting a stimulus and correct phase/cycle value

Hi all.
I just recently discovered Psychopy and being studying it since then, so accept my apologies if these doubts are answered elsewhere.
I’ve found information on the forum describing 1 phase = 1 cycle and in the documents quoting:

“A phase of 0.25 will cause the image to shift by half a cycle…”

Wich one would be correct?
Is it possible to drift the stimulus in a direction on a constant “units” per second basis using phase when dealing with a GratingStim (e.g. 10deg/s to the right)?
Thanks in advance.