When considering the cost of roofing materials, many people take into account just the shingle prices. This is incorrect, as a roof made just of roofing shingles will not work. You also need to consider all the accessories that are included in a complete roof system.
The differences between emails and letters is that, emails are send electronically and arrives faster to the person that you are sending it too, while in the other hand letters takes a little bit longer to arrives to the person and can be lost from the mailing company especially whens sending it overseas also it cost money.
The Purposes of Business Letters. Business letters can be written to employees or managers, as well as clients and prospective customers. The business letter is a formal type of communication that is usually typed on 8 1/2 by 11-inch white stationery paper.