How to Create a Site Collection in SharePoint Online?

Requirement: Create new site collection in SharePoint Online

How to Create a Site Collection in SharePoint Online?
Site collection in SharePoint is a logical group sites with a common top-level site and/or zero or more subsites organized as a hierarchy. Every site collection share common top site, navigation, security, content types, etc. To create a SharePoint Online Site collection from Browser, follow these steps:

Login to SharePoint Admin Center as a tenant admin or SharePoint Online Administrator.
Click on "Site Collections" from left navigation >> Click on "New" >> and then "Private Site collection" to create a new site collection.
The New Site Collection page appears. Set properties according to your requirement to create site collection. Such as:

Title and description for your new site,
Site Address (URL path) for the site
Select the Template for your site collection, typically "Team Site" will do.
Set the storage quota, Site collection Primary owner for the site collection.
Click OK to start creating new site collection. Wait for a moment and your site collection should appear in the site collections list.
Wait for a minute and this creates a new site collection in SharePoint online.

Create Modern Site Collection in SharePoint Online:
To create modern team site collection in SharePoint Online, use use "New SharePoint admin center"

Go to new SharePoint Online Admin Center >> Click on "Create" from "Sites >> Active Sites" node
Pick either "Team Site" option to create a modern team site collection with Office 365 group or "Other Options" to create a modern team site without Office 365 group.
Pick the template as "Team site", Provide a Name, Administrator options and click on "Finish" to create modern site collection in SharePoint Online.