What is a Google Penalty?

Google penalties occur when a website violates webmaster guidelines from manual actions or algorithmic adjustments. However, algorithmic adjustments aren't necessarily penalties. Instead, they result from a site's ranking changes because of how Google's algorithm changes. On the other hand, manual actions come from developers or website users making a change that Google doesn't support or find to be a best practice (such as neglecting to add a privacy policy or making your website ADA compliant).