As you browse the Internet windows creates many temporary files, histories of what sites you visit and any saved information such as passwords, cookies etc relevant to that page
Overtime these files build up and slow down your computer, so it is worth regularly deleting them
Google Chrome
This can be done within Google Chrome, but clicking the menu icon (three dots) as shown in image below and selecting More tools > Clear browsing data

You will then see the window below where you can change options if required and then click Clear data
N.B. If you are signed in to a Google Account and use Google on multiple devices this will clear browsing data across ALL devices - if you do not wish to do that then click sign out at bottom of window BEFORE clicking Clear data

Microsoft Edge
To clear temporary internet files from Microsoft Edge click the menu icon (three dots) as shown in image below and selecting History > Clear browsing data

You will then see the screen below where you can choose a Time range e.g. Last hour / Last 7 days / All time, what data you wish to clear and then click Clear now
N.B. If you are signed in to a Microsoft Account and use Edge on multiple devices this will clear browsing data across ALL synced devices - if you do not wish to do that then click turn off sync at bottom of window BEFORE clicking Clear now

Internet Explorer
This can be done from within Internet Explorer by clicking the icon in the top right corner and choosing Internet options

From the General tab click Delete... in the Browsing history section as shown above

You can then choose which items you wish to clear and press Delete to remove them