COIN
Coin, for instance Bitcoin, is a crytocurrency type which operates independently of any other platform. In other words a coin has its own platform which is called blockchain. There is no difference between a coin and a cryptocoin or altcoin; coin is just an abbreviation of cryptocoin. Altcoins simply refers to coins that are an alternative to Bitcoin. The majority of altcoins are variants of Bitcoin, built using Bitcoin’s open-sourced, original platform with changes to its underlying codes, therefore creating a brand new coin with a different set of features.
Examples of altcoins; Namecoin, Peercoin, Litecoin, Dogecoin and Auroracoin . There are other altcoins that aren’t derived from Bitcoin’s open-source protocol. Rather, they have created their own Blockchain and protocol that supports their native currency. For example; Ethereum, Ripple, Omni, Nxt, Waves and Counterparty. But how can you identify if a coin has its own platform or not ? It is easy; if you check the
https://coinmarketcap.com/, you can see whole list of coins along with their applicable platforms at all.
TOKEN
Tokens require another platform such as Ethereum or Omni to exist and operate. First, tokens provide a way not only to define a protocol, but to fund the operating expenses required to host it as a service. Bitcoin and Ethereum have tens of thousands of servers around the world (“miners”) that run their networks. They cover the hosting costs with built-in mechanisms that automatically distribute token rewards to computers on the network (“mining rewards”).
Second, tokens provide a model for creating shared computing resources (including databases, compute, and file storage) while keeping the control of those resources decentralized (and without requiring an organization to maintain them). This is the blockchain technology which allows shared datas to be stored on a decentralized network.