A token is not necessary an entire word: it can be defined as a small unit of text that gets processed by a language model.
It can be a full word, part of a word, or even punctuation depending on how the text is split and mapped to IDs by the tokenizer.
E.g. the sentence Sorry Dave, I can't do that can be broken into tokens like this:
19152 --> Sorry
20238 --> Dave
11 --> ,
358 --> I
646 --> can
944 --> 't
653 --> do
429 --> thatThe ID mapping is necessary to make the model ingest the tokens.
There are various way to split a sentence into tokens, like BPE.