In the formal offer letter, provide comprehensive details about the position, compensation, benefits, and other pertinent terms. Both the offer letter and employment agreement serve the same basic purpose – to memorialize in writing the terms and conditions of employment.The offer must be communicated to the other party. The offer must contain conditions or terms. An Employment Offer Letter provides the employer with an opportunity to formally make an employment offer to an employee in a clear and concise fashion. Need help drafting a job offer letter? It provides important information including start date, compensation, benefits, and any conditions to employment.