What is a DeFi Aggregator in Ethereum?

Ethereum is where DeFi resides. 

There are alternative platforms where DeFi is also picking up: Binance Smart Chain, IOST, and others.

DeFi is possible in any public ledger as long as it is equipped with smart contracting capacity.

DeFi, in essence, is an umbrella term describing, among other innovations, token swapping.

From token swapping, there are DeFi aggregators.

And here is their functions:

A DeFi aggregator brings trades across all DEXes to a single interface. By doing, a trader gets the best price, saving time and resources of otherwise manually comparing prices across different DEXes.

Users also are on top of proceedings and won't have to register, submitting personal information. Every aspect of a DeFi aggregator, like DeFi operations, is non-custodial without intermediation.

The benefit of an aggregator is the trade optimization capability. 

But there is more. 

A typical aggregator will also automatically allow traders to compare and adopt the best trading strategies. Any strategy incorporated by a trader is implemented transparently, leading to a collaborative and open trading experience that benefits the community.