Sorry this is a bit tech but Ill try and keep it basic. Many years ago while I was at university I remember sitting in a PC hardware class. The teacher had split the class into pairs and given each pair a piece of PC hardware we had 10 minutes to discuss with our partner what the item was and then we had to stand up and explain our item to the rest of the class. I had been paired with one of my oldest friends and both of us had been building PCs for many years compared to the rest of the class who mainly had problems just switching them on. The item we had been given was a PC mother board. We took one look at it both nodded then spent the next 10 minutes chatting about everything but what we supposed to. The teacher noticed this and instructed us to talk about the item in question. We explained that we both knew what it was and had nothing further to discuss (seriously we said this politely not arrogant at all). This enraged the teacher and she decided to try and make an example of us so she told us to get up and talk about our item first. We did, explaining to the rest of the class what the mother board did and why. The fact that we got it spot on enraged the teacher even more as she expected us to not know a thing. So pointed at the CPU slot and asked what that is? Again we gave a spot on answer she started pointing at various other parts asking what it was and each and every time we gave spot on answers. A few people were actually starting to giggle at the teacher she was trying so hard to find something we didnt have an answer for.
Then she points at a rather odd slot which stumped us for a second as it looked similar to a PCI slot but was on the complete opposite side of the board to the other PCI slots. We both figured it must be something specific to the board and said its probably some kind of expansion slot possibly for extending cache etc (this was a back a few years). The teacher lit up with joy and proclaimed that it was an "AGP slot used for graphics cards and sound cards" (AGP was new at the time). We both looked at one another doing the one eyebrow stare and tried to explain that cant be right as 1) its on the wrong side of the board and 2) AGP stands for Accelerated Graphics Port so its very unlikely it was designed with sound cards in mind. But the teacher would not let us say another word and told us to sit down, she was victorious. I still worry about what nonsense she taught other classes over the years and I bet she probably still there today.