One of the biggest issues people come to us to solve is making their blog load faster. This is often the first challenge a growing blog faces. Eventually, your blog will become popular enough to necessitate upgrading your hosting plan. However, there's a lot you can do to put that day off for quite a while.
One of the first and most powerful things you can do is cache your homepage and posts.
What is a "cache" ?
To understand how caching works, you first have to understand a little about how Wordpress works. Without caching, here's how your blog works. When someone browses over to your site, Wordpress immediately queries your Wordpress database for all of the content and settings on the page.
A query is like a search. The site script searches the database for the appropriate content to display on the page. Every time the page is called upon by a user, the database is queried again and again. This repeated database query will eventually cause a tremendous amount of stress to the server.
The result is that pages start to load slower. Eventually, they may start timing out all together.
Here's where caching kicks in. You are probably not updating your site thousands of times a second, right? So why should the system have to query the database over and over again for each new user that comes to the site? For example, the homepage is going to look the same for me as it did two seconds ago when you checked it. It will probably still be the same 10 minutes from now when the next guy checks.
So, what if you could query the database, and then show just the results over and over again without re-querying the database? Well, that's what a cache is.
Your site cache will save the results as a new file, and just reserve it to the next user in line. If an update to the site is made in the mean time, the cache will be cleared out for that page to reflect the new pages.
The cache will then conserve some of the load that your server faces.
Wordpress has a great plugin called WP-CACHE that handles all of this for you.
Another way to save valuable load time is to limit the amount of external content feeding into the site. If you have a lot of third party widgets and banners, they will cause your site to load slower. Loading all of that external content will slow your site because it needs to leave your server to fetch the content. Cut back on the number of ads and outsize sources you use, and you should be in better shape.