No, not everything with everyone. That would be wrong and insane
Here's from official documentation: (click on link to see everything, I'll just quote up a few paragraphs)
WITH OTHER PAYPAL USERS
When transacting with others, we may provide those parties with
information about you necessary to complete the transaction, such as
your name, account ID, contact details, shipping and billing address,
or other information needed to promote the reliability and security of
the transaction. If a transaction is held, fails, or is later
invalidated, we may also provide details of the unsuccessful
transaction. To facilitate dispute resolution, we may provide a buyer
with the seller’s address so that goods can be returned to the seller.
The receiving party is not allowed to use this information for
unrelated purposes, such as to directly market to you, unless you have
agreed to it. Contacting users with unwanted or threatening messages
is against our policies and constitutes a violation of our User
Agreement.
If someone is sending you money and enters your email address or phone
number, we will provide them your registered name so they can verify
they are sending the money to the correct account.
WITH THIRD PARTIES
Members of the PayPal corporate family, such as PayPal Credit, Venmo
or Braintree, to provide joint content, products, and services (such
as registration, transactions and customer support), to help detect
and prevent potentially illegal acts and violations of our policies,
and to guide decisions about their products, services, and
communications. Members of our corporate family will use this
information to send you marketing communications only if you have
requested their services. Financial institutions that we partner with
to jointly create and offer a product (including but not limited to,
the PayPal Extras credit card where we share information with
Synchrony Bank, for example, in connection with pre-approved offers
for the PayPal Extras credit card). These financial institutions may
only use this information to market PayPal-related products, unless
you have given consent for other uses.
