As a PhD scholarship student, you will have four years to dedicate to the preparation of your doctoral thesis. You will have minimal involvement in other tasks, such as teaching assignments or providing services. Given the fact that you are not joining an existing research project, but writing your own application text, you will be given the opportunity to utline your research path in consultation with your promoter.
You do not apply for a vacancy, but submit your PhD proposal to a funding institution (BOF, FWO, IWT) independently. You are therefore in direct competition with numerous other applicants. Depending on the quality of your study results and/or your application text, you may or may not be selected for funding. Depending on the chosen funding chanel, more weight may be attached to excellent study results, or to your capacity to defend your research proposal orally in front of a jury.
More specific information with regards to deadlines and conditions can be found on the page scholarships and mandates.