Letter H7 terms in the glossary

A bounce with an unrecoverable cause: the address doesn’t exist, the mailbox has been deleted, or the recipient’s server rejects the message permanently. Unlike a soft bounce (full mailbox, temporary outage), resending won’t help.

Addresses with a hard bounce need to be removed from the list right away. Persistently sending to them signals to mail providers that the list isn’t being maintained.

The percentage of messages rejected permanently. A high rate points to an old list, or one built from addresses no one has verified.

Mail providers read it as a sender-quality signal - once a threshold is crossed, they start throttling delivery even of messages that would have reached valid addresses.

HTML tags that divide content into levels of importance, from H1 to H6. They make it easier for readers to scan a page, and for search engines to understand what is the main topic and what is a subtopic.

The H1 should appear only once on a page and contain the most important keyword — of all the headings, it is the strongest signal of the page's topic.

A model in which WordPress is used solely to manage content, which is then fetched via an API (REST or GraphQL) and rendered by a front end built in a different technology - Astro, React, Vue.

It gives performance and flexibility on the front end while keeping an editing panel the content team already knows. It costs more upfront and requires maintaining two layers instead of one, so it makes sense where speed or a non-standard interface matters.

An overlay on a page screenshot showing the intensity of clicks, cursor movement, and scroll depth. It reveals things numbers alone don’t show: buttons nobody notices, and elements clicked even though they aren’t links.

Good for forming hypotheses, not for settling them. Conclusions drawn from a heatmap are verified with an A/B test - the map alone shows what’s happening, not why.

The main, usually first subpage of a site - a company's virtual storefront and often a visitor's first contact with the brand.

The arrangement of elements, consistent design, and clear, distinct messaging on the home page determine whether a visitor stays and goes further, or closes the tab within seconds.

The foundational language of web pages. It describes what a given piece of content is: a heading, a paragraph, a list, a table, a link, or an image. CSS handles appearance, but without HTML there is nothing to style.

Correct HTML structure is the foundation of accessibility and SEO - a screen reader and a search engine’s bot understand a page exactly the way its markup describes it.