The most important terms for panorama photography
To understand what a cylindrical panorama is, imagine that you are in a giant glass with photos glued to the wall. A spherical panorama is like being inside a giant sphere surrounded by photos. A spherical panorama is pretty the same as how we see the world with our own eyes.
Parallax is the mismatch between frames which were shot from different directions. It emerges due to the laws of optics. Sometimes it’s not important, and sometimes to fix it on a computer is quite hard. Parallax can be avoided by turning the camera only around the nodal point.
Nodal point is a special point in space. If you turn a camera around it, you will not have problems with the parallax error. Just imagine that the camera is stuck to some point in space and you can turn it only around this spot; you cannot drag it away. If you are rotating the camera in any other way (not around the nodal point), there will be a parallax error.
This is a special head for the tripod. With this head the camera rotates exactly around the nodal point. This eliminates errors, which makes post-production easier. There are some cheap models even for smartphones.
Hotspots are areas in the panorama which react to the mouse hovering or clicking. There are two kinds of hotspots: point hotspots and polygonal hotspots. A point hotspot is like an icon and a polygonal hotspot is like an active area on the panorama. They look different but can be used to do the same. For example, you can use both types of hotspots to make transitions between locations.