There is process of getting offer letter and appointment letter. An appointment letter or employment letter is a formal letter provides in writing to a selected candidate joining for employment. Appointment letters are generally provided after offer letter on the first day of the candidate starting work or after the completion of the training.
Generally appointment letter describe all the terms and conditions of the employment and other company policy adherence. Mainly appointment letter describes in length the position offered, salary structure, company benefits, confidentiality policy of the company, work policy, starting date, and important information about the employment.
The candidate generally would receive this appointment letter on the first day after beginning employment and would return a signed copy back to the employer indicating acceptance of the appointment letter.
Check here the sample of an Appointment Letter