When you look down the bore of a typical cylinder, the transfer ports are between the exhaust port and the intake port. Say we look down the bore of a zeta 50cc kit for puch. This is what you'll see:
The intake port and boost ports are up top, they're the ones that look like a face. The exhaust is the biggest port, the one on the bottom. The transfers are on the sides. This kit has bridged transfers, meaning that the transfer ports were wide enough that they put a bridge in the middle of them to keep the piston rings from bulging into the ports. By the way, you're looking through the cylinder from the cylinder head side, not from the case side, that's why the exhaust is the closest port to the viewer. If you were looking through it from the case side, the intake port would be closest.
Now imagine you took a piece of paper, and put it inside of the cylinder, and rubbed a crayon or something on it. You would be making a 'map' of the port layout, or a 'portmap.' Here's what the port map of a puch 65cc metrakit looks like.
The arrows that are pointing up show the distance to the top of the cylinder, where the cylinder head bolts on. Notice that the exhaust port is the one closest to the cylinder head, the transfers are the next closest, and the intake is the farthest away. This portmap is weird in that the intake port is wider than the exhaust port.
Here's another portmap:
On this one, the person who made the port map only shows us one set of transfer ports, instead of both, because the second set will be identical to the one they _did_ show, just on the other side of the exhaust port. This portmap is nice, because each of the ports is labeled. The ports with the "T" in them are one set of transfers, and the ports with the "B" in them are boost ports, right above the intake.