Basically, an article is a body of text that imparts information. Whether this is done in a scientific language, with an informal voice or in a more serious manner, is usually decided by the subject and type of article, and to whom it is aimed.
A scientific or medical article aimed at professionals will use the first example, i.e. scientific language. The same article aimed at the general population must be written in laymans language that everyone can understand. An article written on a serious subject should have a similar tone of writing, while something aimed at teens or young adults about entertainment, clothing or sport eg, will take on a bright and more breezy note.
To get a human face on the issue being discussed in an article, many editors require two anecdotal pieces to be included. These will come from interviews with people who have first hand experience of the topic. In an article about home-schooling for instance, you can interview people whose children are home schooled. If you dont know of anyone, support organizations can help by supplying names and phone numbers. They are willing to do this because your article will help to spread the word...