You may remember the variable-as-a-box metaphor that I used to introduce variables.
You need to learn about this distinction as these two kinds of objects (values) behave very differently under some circumstances, which is both good (power!) and bad (weird unexpected behavior!) news.
These are mutable, like lists in contrast to “normal” immutable values (integers, floats, strings). 10.2 Variables as boxes (immutable objects)
