How an Ethereum smart contract recognizes other cryptocurrencies

[cryptedlife]

Technologically, blockchain platforms don’t know there are other cryptocurrencies and work only with their native coins. For instance, Ethereum can’t recognize anything but ETH. But what if you want to accept other coins during ICO and notify smart contract about external transactions? Read more here:
http://blog.blockstarter.co/en/ethereum-smart-contract-recognizes-cryptocurrencies/