A title tag is the 50-60 character text used to describe the online documents on your site. This element is considered one of the most important components to On-page SEO. 

These could be blog posts, pages, media files and anything else with an accessible URL your site.



As you can see in the example above, the title tag is used on search engine results pages or SERPs.

I will leave the formatting suggestions up to the great people at MOZ:

Many SEO firms recommend using the brand name at the end of a title tag instead, and there are times when this can be a better approach. The differentiating factor is the strength and awareness of the brand in the target market. If a brand is well-known enough to make a difference in click-through rates in search results, the brand name should be first. If the brand is less known or relevant than the keyword, the keyword should be first.

So, it centers around where to put separators, content and your branding.  Here are some examples:

The other formatting difference is the separator that is used.

Title Separator

You are fine using any of them and it's down to personal preference, although we use a pipe "|" because it tends to be more clear.

We aren't married to using any particular separator though. We have a global setup for almost all of our pages to use the "|", but we do switch it up and use any of the others when it looks better.