How caching works
A page on a typical content-managed site does not exist until someone asks for it. The server runs code, queries a database, assembles the template and sends the result. Caching saves that finished result so the next visitor gets the stored copy instead of paying for the same work again. Nothing about the page changes; only the amount of work behind it does.
It happens in layers, and confusing them is the source of most caching problems. The browser keeps files it has already downloaded, so a returning visitor need not fetch your logo again. A page cache on the server holds whole assembled pages. An object cache stores the results of database queries for the code to reuse. A content delivery network holds copies in several countries so the file travels a shorter distance. Each layer has its own rules about how long a copy stays valid and what clears it.
Why caching matters
The visible benefit is speed, and speed is not a vanity concern. A page that assembles itself for every request slows down exactly when it is busiest, so a campaign that works is also the thing that makes the site crawl. Cached pages absorb that traffic with far less strain, which matters most on shared hosting where processing power is the scarce resource.
It also shortens the wait before anything appears at all, which feeds the loading measurements Google reports. For visitors on mobile connections — the majority of traffic in Nepal — a saved copy served from nearby is often the single biggest improvement available without redesigning anything.
Common mistakes with caching
The classic one is editing a page, seeing no change, and editing it again. The old copy is still being served, so the fix is to clear the cache rather than to rewrite the content. The mirror image is worse: a cached copy of a page that should never be shared, such as a logged-in dashboard, a basket or a checkout, shown to the wrong person.
Stacking plugins causes its own trouble. Two caching tools fighting over the same pages produce results neither one predicts. And caching hides slowness rather than removing it: if the underlying site is heavy, the first visitor to every uncached page still waits, and so does any page a cache refuses to store.
How to act on it
Decide what must never be cached before deciding what should be. Carts, accounts, checkout and any page showing personal information are excluded first. Then let static assets — images, stylesheets, scripts — be stored for a long period, and give pages a shorter life so edits appear without anyone intervening.
Make clearing the cache a documented step after publishing, and test in a private browser window rather than the one you have been working in. Watch the forms in particular, because a cached page can hold a security token that has already expired and quietly reject submissions. Treat caching as one part of page speed work, not the whole of it: a stored copy of a bloated page is still a bloated page.