As @erominer stated, tokens could also be considered altcoins. What you may be asking is the difference of a cryptocurrency coin from a token.
Tokens typically run on an actual coin's blockchain and are intended for very specific uses, decided by their issuer. Think about the old days when you had to buy tokens to play at an arcade. You can only really use them in that arcade even if they technically have value. That's basically how cryptocurrency tokens work.
Coins, on the other hand, have a blockchain of their own, and generally act as actual currencies that can be used to buy goods/services anywhere.
Edit: Jet Cash beat me to it, but that's my explanation anyway.
I totally agree with your explanation. Moreover, there are 3 types of token:
1. Security token: it's also called digital token which represents a product or physical asset
2. Utility token: it supports token holders to access services which are provided by the issuer
3. Equity token: it's also called tokenized securities and it's similar to stock in Joint-Stock Company
Token is understood as parasite/sponger in a certain blockchain of the coin because it doesn't have it own blockchain, for example: EOS, CS, BITX, HAV etc...is Ethereum based; TKY, QLC, DBC etc... is NEO based and so on