The colours used
Deliverable one: Document with the exact colours used
E.g. The brand colours used in this logo are:
Deliverable two: Logo in a vector format, ideally SVG
Must include the logo in SVG format:
Why? Because then can be scaled to any size in the future.
Deliverable three: logo in PNG format with transparency, where relevant.
logo.png with transparency
Deliverable four: Examples of the logo being used in light and dark background contexts
Show the logo being used in both a light and a dark background scenario. Understand this might require more than one colour variation of the logo (if this is a suprise, you have not finished the design process).
Why? You want to avoid at every possibility a client self editing their own logo. Deliver to them a collection of logo formats which are suitable in both scenarios and go further to attach examples of the logo being used in those different contexts (light and dark).