Protocols are the biologist term for "recipe".
I found that a lot of biology comes down to this: get the right recipe, follow it well even though you don't understand all the proprietary details, and pray.
Kit to extract clean DNA from water.
Figure 1. Qiagen DNeasy PowerWater Kit open box. Source.
Removes PCR byproducts from purified DNA.
Repairs the ends of DNA, and also attaches an adapter protein to the DNA that makes them go through the pores of e.g. an Oxford Nanopore MinION.