Importance of Semantic HTML To SEO and Accessibility.

When it comes to SEO:

1. Enhances understanding; Search engine uses semantic HTML to better understand the context in the web.
2. Keyword importance; Helps the search engine in identifying the keywords use like,

   .

When it comes to Accessibility:
1.Enhanced screen reading compatibility; Provides meaningful structure which is important to visually challenged.

1. Improved keyboard navigation; It provides accessibility by providing sensible elements like buttons
2. Compatibility with other technologies; It allows compatibility with accessibility features with browsers and operating systems like text resizing.

In conclusion semantic HTML is helpful in in improving visibility but also it ensures accessibility to all users.