Ask HN: What info someone can access if they know my Gmail password?

Today, our placement cell of University forwarded a message about the recruitment process of a company

The company asked the students to create a account on their website with the same password of their personal email ID in their message.

Here's the message

  Hi,
  Please find attached the 
  [Company Name] Application 
  Process Guide and 
  instruction below. Please 
  request students to go there 
  the instruction and attached 
  ppt before taking the test.
 
  Please ask them to use 
  Chrome to access the link 
  for test and once they open 
  Chrome they have to 
  type [Registration Link]   
  and start registering please 
  ask them to keep trying to 
  login twice or thrice if 
  they face any error/problem.
 
  Note: Please ask them to 
  give their respective roll 
  number as user name and let 
  the password be the one 
  which they use for their 
  personal mail to access. 
  They have to give only their 
  personal email id while 
  registering and not their 
  college id because all the 
  test links will be set to 
  their personal email id 
  only.

Majority of the students are using Gmail. So, what information they can access if they know my Gmail password?