Where is a meta description tag used?
A meta description tag is placed in the <head> section of an HTML page. An effective meta description is unique, meaning that the content should not be the same as the meta description tag of other pages within the same website.
In addition, it's recommended that the meta description should be no longer than 155 characters in order for the text not to be cut off when the meta description tag is displayed in the search engine results page (SERP).
If the meta description tag exceeds 155 characters, there's a risk that the search engine indexing robot decides to replace the meta description with a self-made snippet, resulting in less control over how the website is shown in the SERP, the search engine results page.