I/O usage (Input/Output usage) refers to the amount of data transferred between your website's storage (like hard drives or SSDs) and the server's memory or network. Every time your website reads a file (e.g., loading an image) or writes data (e.g., saving a form submission), it consumes I/O resources.

Think of it as the traffic flow between your website's storage and the server. High I/O usage can slow down your site if limits are exceeded, similar to a traffic jam. Common causes include:

• High traffic spikes
• Unoptimized databases with frequent queries
• Large file uploads/downloads
• Poorly coded plugins/themes making excessive disk calls

To manage I/O usage effectively:

1. Use a Content Delivery Network (CDN) to offload static files.
2. Optimize your database regularly and use caching (e.g., Redis).
3. Choose a hosting plan with SSD storage, which handles I/O faster than traditional HDDs.
4. Monitor usage via your hosting control panel and set up alerts.

If you consistently hit I/O limits, consider upgrading your hosting plan or optimizing your site's performance. Efficient I/O usage ensures faster loading times and a smoother experience for your visitors.