CoinZoom uses a smart contract when sending  ETH or ERC20 .

Whenever a smart contract needs to send ETH or execute some other code on its own, they call a function which was eventually labeled as an ‘internal transaction’.

This name does not correctly reflect what is happening, as internal transactions are not actually included directly in the blockchain. They are a result of smart contract functionality.

Nevertheless, they are reflected in the balance of the receiving wallet address

They can usually be found under in the summary right above the "Value" row and an ‘Internal Transaction’ tab, via

An Example:

The Value shows as 0 Ether, however the summary above that shows the entire transaction clearly shows that 1 Ether was sent to the target address.