There are many different forms of digital marketing that businesses can use to reach their target audiences. Some examples include:

1. Search Engine Optimization (SEO): This is the practice of optimizing a website and its content to improve the website's visibility and ranking in search engine results pages (SERPs). This can be done through techniques such as keyword research, content creation, and link building.

2. Pay-per-click (PPC) advertising: This is a form of digital advertising in which businesses pay each time their ad is clicked. PPC advertising is typically managed through platforms such as Google AdWords or Bing Ads.

3. Social media marketing: This involves using social media platforms such as Facebook, Instagram, and Twitter to promote a business's products or services. Social media marketing can take many forms, including creating and sharing content, running social media ads, and hosting giveaways or contests.

4. Email marketing: This involves using email to reach out to a list of subscribers and promote a business's products or services. Email marketing campaigns can be used to nurture leads and build relationships with customers.

5. Content marketing: This is the practice of creating and distributing valuable, relevant, and consistent content to attract and engage a specific audience, with the goal of driving profitable customer action.

6. Influencer marketing: This is a way for brands to reach new audiences by partnering with individuals who have large followings on social media. The influencer will promote the brand to their followers and may receive compensation in the form of money, free products, or other benefits.

7. Affiliate marketing: This is a type of performance-based marketing in which a business rewards one or more affiliates for each visitor or customer brought about by the affiliate's own marketing efforts.

8. Marketing Automation: This is the use of software and technology to automate, streamline, and measure marketing tasks and workflows to boost efficiency and effectiveness.

These are just a few examples of the many forms of digital marketing that businesses can use to reach and engage their target audiences. The best approach will depend on the specific business and its goals.