Please help me About Tier 2 priority Application

[reflection]

Hello Everyone,

i need help about tier 2 application. if everything goes well i am going to apply Tier 2 Visa. to get visa result quicker i wish to go for In Person service, but today i got another information about Tier 2 Priority application. now i am completely confused to understand what is the difference between In person service & Tier 2 Priority application.
Tier 2 Priority application service, can i choose this way to apply or submit application? or its for other visa category or customize visa applicant. is it only for tier 2 extension or new applicant can apply??

to use this service shall i need to take assistance of legal authority or can do by myself?

please help me about this, it will be greatly appreciable.

Thanks