All modern browsers keep some part of information received. It does so in order not to download elements of web pages again. It can be the reason of difficulties when the website is updated. For example, your developer had updated the style of pages, but you don’t see these changes. Browser cache can be the reason of it.

Google Chrome:

Ctrl+Shift+Del (Mac: ⌘-Shift-Del) Read more: https://support.google.com/accounts/answer/32050

Mozilla Firefox:

Ctrl+Shift+Del (Mac: ⌘-Shift-Del) Firefox → Settings → Privacy and security → Clear Recent History → Clear Now Read more: https://support.mozilla.org/ru/kb/kak-ochistit-kesh-firefox

Internet Explorer:

• Ctrl+Shift+Del → Clear browser cache → Delete

Safari:

• Ctrl+Alt+E → Clear
• Ctrl+Alt+E → Empty cache (Mac: ⌘ → Privacy → Remove All Website Data)

Opera:

• Ctrl+F12 → Advanced → History → Disk Cache → Clear