For details, you can also check out these resources:<\/p>
- Caching for WordPress, Explained in Plain English<\/a><\/li>\n\n
- Browser Cache vs Cookies: What\u2019s the Difference?<\/a><\/li>\n\n
- What is Object Caching and How to Use It With WordPress<\/a><\/li><\/ul>
What is OPcache or PHP Opcode Caching?<\/h2>
OPcache is a type of OPcode caching<\/strong><\/a>.<\/strong> This kind of caching compiles human-readable PHP code to code your server understands which is called opcode. This occurs when the PHP file loads on a web page for the first time. Then, it\u2019s saved to the server\u2019s memory for faster loading at each subsequent page visit.<\/p>
Bytecode cache engines such as OPcache<\/a>, APC<\/a>, and Xcache<\/a> all complete this process the first time the PHP file is executed without having to do it a second, or third time.<\/p>
How PHP Opcode Caching Works<\/h3>
When a PHP script executes, your server\u2019s cache memory is checked to see if the script has already been cached. If it hasn\u2019t, it\u2019s parsed, which means the code is analyzed.<\/p>
Then, the script is compiled into opcode making the file readable by the server. Once that\u2019s done, the opcode is saved to the server\u2019s memory.<\/p>
In other words, it\u2019s stored in your server\u2019s cache. The next time a visitor loads the page with the PHP script, the cached code is executed and loaded much faster.<\/p>
On the other hand, if the script is loaded on the page and the cache is checked for opcode and finds it, then it\u2019s loaded lickety-split.<\/p>
![\"When](\"https:\/\/wp-rocket.me\/wp-content\/uploads\/2023\/04\/wp-rocket-opcache-execute-code.png\")
When PHP scripts aren\u2019t in the cache, they\u2019re cached for subsequent page loads.<\/em><\/figcaption><\/figure> The Differences Between OPcache and APC Caches<\/h3>
OPcache, APC as well as Xcache are all opcode caching systems. OPcache used to be owned by Zend and Alternative PHP Cache (APC) was a free, open-source extension for PHP. Xcache was also an alternative option.<\/p>
APC was widely used, but it didn\u2019t have the backing that OPcache had so it could be well maintained and stable with each new PHP release.<\/p>
Fortunately, Zend made OPcache open source and available as an extension since PHP version 5.5. In earlier versions, you have the choice to use APC or OPcache, but if you would like to use the latter, you need to manually install it.<\/p>
Xcache, on the other hand, is a good alternative to OPcache as a PHP accelerator.<\/p>
Will OPcache Speed up My WordPress Site?<\/h3>
- Browser Cache vs Cookies: What\u2019s the Difference?<\/a><\/li>\n\n