That is the section on the Energi Core Wallet called PrivateSend and Start Mixing.
PrivateSend gives you true financial privacy by obscuring the origins of your funds. All the Energi in your wallet is comprised of different “inputs” which you can think of as separate, discrete coins. PrivateSend uses an innovative process to mix your inputs with the inputs of two other people, without having your coins ever leave your wallet. You retain control of your Energi at all times. The purpose behind PrivateSend is to maintain the privacy of your Energi coins by removing its history from the Energi network.
Check out the basics of this here: https://medium.com/energi/energi-privatesend-explained-2258cd166a2b