low speed
The internet is very slow checked every thing and use mobile internet
still slow
Question marked as
Please download and run EtreCheck, and share the report to the clipboard. Then open a new reply here, and use the Additional Text button that looks like a printed page to get a text input box big enough to paste the hardware and software configuration report here, and paste it.
The iMac 8 GB / HDD configuration is often with performance complaints, though there can be other problematic configurations and other issues.