New ask Hacker News story: Ask HN: Common Misconceptions about Computers?

Ask HN: Common Misconceptions about Computers?
2 by qntty | 2 comments on Hacker News.
One of my favorite experiences is learning that something that I thought was true isn't. All the better when other people think it's true too. What are your favorite misconceptions about computers? Some that come to mind for me are: (1) The idea that relational databases are named "relational" because they allow you to represent relationships between tables. Actually, "relational" refers to the fact that they are modeled as relations (aka tables). A relational database would be just as relational if it was only capable of storing a single table. (2) The idea that HTTP "packets" are the same sort of thing as TCP packets. I used to imagine HTTP headers being attached to the beginning of every TCP packet when communicating over HTTP. Of course TCP doesn't present a "packet" interface at all. It's just a stream of bytes, so an HTTP packet is just a division within the stream of bytes, defined by the Content-Length header. (3) The term C in ACID and the C in CAP refer to the same concept of consistency. Actually, ACID consistency is a single-node property, whereas CAP consistency is a multi-node property. One is about maintaining uniqueness and foreign key constraints, whereas the other is about making a multi-node system appear to behave like a single-node system.