Where Does My Money Go After I Open a Solo 401k?

In a typical corporate 401k, the plan is managed by the company you work for. However, with the Solo 401k the plan is connected to your company. Therefore, you can manage the plan. This freedom is called checkbook control and it's vital to a self-directed Solo 401k.

https://www.solo401k.com/blog/basics-where-does-money-go-after-solo-401k-is-open/