Definition:

Provisional Applications

• Filed to secure the priority rights (i.e. to officially ascertain that you have come up with the idea first).
• Filed as soon as you have rough draft of your invention and implementation can be done within next 12 months
• Do not contain any claims and are easier to draft
• provide just the basic details of invention and the novelty without providing much details on implementation part.
• Provisional applications are never published and are never granted. These never come to public domain

Complete Specification Applications

• Much enhanced version of the Provisional application to be filed within 12 months from the filing of provisional application (can also be
  filed directly without a filing provisional)
• Considered for examination and grant.
• Provide complete implementation details, utility details, best mode of operation, etc for the invention
  The complete specification application should ensure that anyone operating in the domain of application subject (e.g. mechanical, etc) will be able to perform the invention using details provided in the application.

Priority Date

• Filing date of provisional and/or Complete specification Application (whichever is earlier)
• However, If application filed in any other country before filing in India - the filing date in that country
• Priority date ensures that any invention related documents published after this date are not considered as novelty breaking for the patent