The Gaussian distribution is the same as the normal distribution. Sometimes, "Gaussian" is used as in "Gaussian noise" and "Gaussian process." See related links, Interesting that Gauss did not first derive this distribution. That honor goes to de Moivre in 1773.

Because very many variables tend to have the Gaussian distribution. Furthermore, even if the underlying distribution is non-Gaussian, the distribution of the means of repeated samples will be Gaussian. As a result, the Gaussian distributions are also referred to as Normal.

yes

No, it is the name given to the Gaussian distribution.

It could be a Gaussian curve (Normal distribution) rotated through a right angle.

It could be a Gaussian curve (Normal distribution) rotated through a right angle.

It could be a Gaussian curve (Normal distribution) rotated through a right angle.

It could be a Gaussian curve (Normal distribution) rotated through a right angle.