RE:8 slices per channel ...... Yes, somebody other than Edgewater using the term "slice": (Is this progress?)
20 MHz Station (20 MHz STA)
Wi-Fi 6 introduced 20 MHz STA, a power-saving device category for IoT devices. A typical channel has eight slices, and depending on need, pieces are assigned to IoT devices. Devices benefit from less contention, longer battery life, and lower latency.
In technical terms, a 20 MHz channel using orthogonal frequency-division multiplexing (OFDM) technology has 242 tones or useful subcarriers. They are sub-divided into smaller groups called Resource Units (RUs). The RU can be as small as 26 tones. The access point (AP) can now assign these smaller RU concurrently to IoT devices needing only a small bandwidth.