Hello.
① Install a HubSpot tracking tag on your existing site
②Create a website on HubSpot
Is there a difference in the data that can be measured in ① and ② above?
In addition, regarding forms, you can also install them on external sites (HTML code) and
Is there any difference in placing it on a HubSpot page?
Hello @木村,
Thank you for reaching out to the Community!
I understand that you’d like to know if there is a difference in data between placing the HubSpot tracking code directly on an external website or use a HubSpot hosted page instead.
You also want to know if there is a difference in data between placing a HubSpot form on an external page or use a HubSpot form on a HubSpot page.
Please let me know if that’s not the case.
I’d like to invite a couple of subject matter experts to this conversation: Hi @Mike_Eastwood, @kmcready and @Aakar do you have any insights to share with @木村, please?
Also, if anybody else has anything to add and/or share, please feel free to join in the conversation 
Thanks a lot and have a lovely day!
Best,
Bérangère