Surge has a cool set of effects, and also works as an audio input source in most DAWs so you can use them using routing and latch mode with the full synth.
But in a couple of situations, it is powerful to have Surge effects as a separate plugin. The Surge Effects Bank plugin allows you to do this - it is included as an extra plugin in the macOS and Windows Surge installers.
To use Surge Effects Bank, simply drop the VST3 or AU into your DAW as a plugin in an effects slot. The controls are fairly obvious, but the knobs adjust various parameters, and the switches allow tempo sync for appropriate parameters.
The one feature Surge Effects Bank offers which is impossible to do in Surge synthesizer invovles the vocoder effect. Vocoder is a powerful tool in Surge, where the sidechain acts as the modulator and Surge itself acts as the carrier. But, using the Surge vocoder with a sound source other than Surge as a carrier would require two sidechains, a feature which is unsupported in most modern DAWs. With the Surge Effects Bank plugin, you can sidechain a modulator in, while also using the current track as a carrier source, allowing other synths or audio sources into the vocoder circuit.