Alignment of the sales and marketing functions exists when the two functions or departments fully understand each other and share a common language, especially as it pertains to customer acquisition.
Ask your sales people what defines a sales lead. Then ask your marketing department. If there is not a common understanding, then you most likely have some aligning to do.
Marketing will often view a lead as a name and a telephone number of somebody who potentially has an interest in your product or service. The sales folks, on the other hand, will often define a lead as a person who has expressed specific interest in your product or service and who has been at least initially qualified by somebody to verify that they have the want, the desire, and the means to purchase such a solution. The two often have a very definition of what a "lead" is.
Without alignment between sales and marketing, there is a disconnect between the two functions. That disconnect hampers success and profitability.