- Cache miss
- A request that full page cache does not answer, so Magento builds the page in PHP against the database. Time to first byte on a cache miss is the server-lane measurement this site asks for; MGT-Commerce's guide puts an uncached page with extensions at 3 to 8 seconds against under 200 milliseconds cached.
- cacheable="false"
- A layout XML attribute on a block. One block carrying it makes the whole page uncacheable, per MGT-Commerce's full page cache guide, which calls it the most common pitfall, and Sonassi's Varnish debugging post.
- Chrome UX Report (CrUX)
- Google's dataset of real Chrome users' experiences, aggregated over a 28-day rolling window and reported at the 75th percentile, per developer.chrome.com. Core Web Vitals are assessed on it.
- CLS
- Cumulative Layout Shift, the visual stability Core Web Vital. Good is 0.1 or less, per web.dev.
- Core Web Vitals
- Three field metrics, LCP, INP and CLS, assessed at the 75th percentile of page loads. web.dev states the good thresholds as 2.5 seconds, 200 milliseconds and 0.1.
- Fastly
- The CDN included with Adobe Commerce on cloud infrastructure at no additional cost, per Adobe's documentation, configured through custom VCL snippets from the Commerce Admin or the API with per-environment credentials.
- Grace
- How long Varnish serves stale content while fetching a fresh copy. elgentos's working group lowered the default on backend responses from 3 days to 1 day; MGT-Commerce's guide recommends 300 seconds.
- Hyvä
- A Magento frontend built on Alpine.js and Tailwind CSS that replaces Luma. The theme is free and open source under OSL 3.0 and AFL 3.0 from 10 November 2025, per hyva.io; Checkout, Enterprise and Commerce remain commercial.
- INP
- Interaction to Next Paint, the responsiveness Core Web Vital, stable since 12 March 2024 when it replaced First Input Delay, per web.dev. Good is 200 milliseconds or less.
- Lab data
- A single throttled run of Lighthouse or PageSpeed Insights on one URL and one device profile. It shows that a change happened in a test, not that any user received a faster page.
- LCP
- Largest Contentful Paint, the loading Core Web Vital. Good is 2.5 seconds or less, per web.dev.
- Luma
- Magento's default frontend, built on RequireJS and Knockout, and the usual cause of INP failures on stores that have not moved to Hyvä.
- Mage-OS
- A community distribution of Magento Open Source. ParadoxLabs states it co-founded it and reports a migration to it on its proof page; elgentos names it among its platforms and Snowdog's Iskra page lists it.
- mview changelog tables
- Tables ending in _cl that record catalog changes for the indexers. When cron stalls they grow until a reindex locks the catalog.
- p75 and p90
- The 75th and 90th percentiles of user experiences. Core Web Vitals are assessed at p75; elgentos argues in its Haibu post that p90 is the number to watch.
- Real user monitoring (RUM)
- A tool that records performance from real visitors' browsers. elgentos publishes a Magento 2 module for RUMvision and used it on Haibu.
- Speculation rules
- A browser feature that prefetches or prerenders the next page. Bemeir's article states Hyvä ships it from version 1.4, defaulted to prefetch, and warns that prerender can fire tag scripts before the shopper arrives.
- Time to first byte (TTFB)
- The time from request to the first byte of the response. On a cache miss it measures the server lane; on a hit it measures the cache.
- Varnish
- The HTTP cache Magento uses for full page cache. MGT-Commerce's guide states 2.4.8 requires Varnish 7.6.
- VCL
- Varnish Configuration Language, the file that decides what Varnish caches and for how long. On Adobe's cloud it is edited through Fastly custom VCL snippets; elsewhere it is the file elgentos's working group rewrote.