Sales people are responsible to generate sales leads, convert leads to actual sales. The key performance indicators are
(1) revenue generated
(2) conversion rate (e.g turn every 3 sales leads into 1 actual sales realized
(3) convert existing unactive customer to active customer
(4) maintain and enhance customer relationship
(5) customer based (e.g. number of the customer)

BD (Business Development ) People are focused in
(1) building partnership and realize sales through partnership. (e.g. building a new sales channel where your product/service can be seen and sold)
(2) building partnership and enhance brand/credibility (e.g. partner with industry leader and have the logo appear on your website or sales material
(3) build partnership and uses other brand product/service (e.g. having Intel CPU in your product and label as Intel inside).

Hope the above gives a quick overview of the differences.