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Are the two structures depicting the same molecule? Why? Why not?enter image description here

(Sorry, I know the picture is crude. I just couldn't help it)

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If ethanol was flat, it would make sense, but it isn't. – Mithoron Mar 3 at 12:29
They can be stereo isomers instead. See… for 3d structure of ethanol. – user19099 Mar 3 at 12:33
If ethanol was static, this would be true, but it isn't. – jerepierre Mar 3 at 16:12
There could be atropoisomers if rotation was blocked but it would need very low temperature to try to separate what is normally rotamers of ethanol. – Mithoron Mar 3 at 22:17

Try to imagine it in a 3D fashion. You can look it at The molecule rotates around the C-C bond converting one structure into the other. These rotations are very fast.

Another point is, that the representations you chose are 2D, so the could still represent the same molecule:

same molecule different angles

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