In SharePoint How to create a form that changes based on a drop down selection -

i need create dynamic form/workflow in sharepoint. trying create form has drop-down selector 2 options projects , proposals. depending on of 2 submitter chooses form change fields displayed in form below them.

the goal have form populate 1 list , populate different fields depending on form type chosen.

is doable?

our sharepoint environment being provided microsoft's office365 solution.

did try content types ? you'll not drop-down (however i've seen drop-down document libraries content types), can achieve target: when creating new item can select type of item create (project or proposal) , when you'll fields according content type. data stored in same table.