Profile details shows you all your settings regarding your account. You can change any detail here that you want.
Important: Timezone in account details is a timezone that you want to see all your data in. If your set time zone under account is EST, all your data (Survey, Responses, Reports etc.) will be shown in EST time zone.
You can also update your payment and billing details from accounts page.
Team management helps you collaborate with your team. You can invite you team member with "Add Member" button.