In marketing, lead generation is the generation of consumer interest or inquiry into products or services of a business.

Leads can be generated for purposes such as list building, e-newsletter list acquisition or for sales leads. The methods for generating leads typically fall under the umbrella of advertising, but may also include non-paid sources such as organic search engine results or referrals from existing customers.

Businesses strive to generate "quality" leads. Quality is usually determined by the propensity of the inquirer to take the next action towards a purchase.

Lead generation is the process of creating sales leads which might convert into sale for the company. The leads may come from various sources or activities, for example, digitally via the Internet, through calls, through advertisement and list purchase. Companies may also rely on referrals, telemarketers, and advertisements to generate leads. Lead Generation is a very popular practice of generating leads in the Business to Business type of sales.

Lead Generation, unlike Demand Generation, is more about actual opportunities (Leads) than creating awareness or demand.
Source: Wikipedia