You can create a lead when identifying potential interest for early-stage prospect management and convert it to a deal when a structured engagement is established, signifying a commitment to pursue the ongoing transaction.
Converting a lead to a deal will move all the interactions from the lead to the deal so that no information or captured communication is lost.
There are 2 ways in neetoCRM where you can convert a lead to a deal
Bulk action from leads dashboard
Lead show page
Whenever you convert a lead to a deal, a Convert to deal form shows up, which is pre-filled with the details. You can update it as needed.