Here is a quick guide and definitions so you can choose the best domain extension based on your circumstances:
- .com, .info, .biz, .org, .net, .name are Global Top Level Domains (or gTLD for short). These do not have much affect on a website’s rankings in search engines (SEO), but users are more familiar with .com,.net, .org domains and if your intent is to service global audience .com is your best choice.
- .pk, .com.pk etc are ‘Country Code Top Level Domains’ (or ccTLD for short) but .PK domains significantly affect the ranking in search engines thus improves SEO of a site among the national search results.