A job offer signed by both parties which states all required information, such as pay, benefits, termination, vacation etc. can be accepted for WP. It is legally different in their functions. Contract is bonding document for your employment with more details. So always good if you can get contract when you formally start working. When you have issues with your ER, you have contract as the document to refer to. In cases no contract signed, the local employment standards will apply.
