There are several types of keywords you should consider:
Short-tail keywords: These are general and have high search volume but are highly competitive (e.g., "email marketing"). Long-tail keywords: These are more specific and less competitive, often leading to higher conversion rates (e.g., "best email marketing strategies for small businesses"). Branded keywords: These include your brand name and are useful for brand-specific searches (e.g., "Mailchimp email marketing"). Transactional keywords: These indicate a user's intent to make a purchase or take action (e.g., "buy email marketing software"). Informational keywords: These are used to provide information or answer questions (e.g., "how to improve email open rates").