In SharePoint versions before 2010 the default page on a
SharePoint site was a web part page, but from 2010 and above
the default team site home page is a wiki page. You
can add text, tables, links, images and also web and app
parts to a wiki page, and you can even link to a SharePoint
page that does not exist yet.
On any wiki page you can do wiki linking, which means you
can link a page that does not exist in SharePoint.
In this Links tutorial in the SharePoint Online from
Scratch series, Peter Kalmström, CEO and Systems Designer
of kalmstrom.com Business Solutions, explains different
ways to create wiki links.
This is what Peter shows in the demo:
How to create a wiki link and then create the page
that the link points to.
How you can see if a wiki linked page exists or
not.
How to link to a particular list.
How to use Ctrl + space to link to a view or to
a particular item in a list.
How to manipulate the link anchor text.
Note that the SharePoint 'Add a page' command gives a modern
page. To create a wiki page in another way than by a wiki
link, open Site contents >Site pages and select 'Wiki
Page' from the '+ New' dropdown.
In SharePoint versions before 2010 the default page on a
SharePoint site was a web part page, but from 2010 and above
the default team site home page is a wiki page. You
can add text, tables, links, images and also web and app
parts to a wiki page, and you can even link to a SharePoint
page that does not exist yet. 
