[Canada]

In the context of this question... early startup... and to really hand waive and simplify things...

The CTO has assemble a team of developers who will build the product or make progress toward that product with reasonable time and cost.

The CEO has to get sufficient attention on that effort to raise the money to pay for continuing it further.

If either fail to deliver in a timely manner, it's over. The more each of you can help with the other's task, the better.