The words diary, journal and blog are terms often used interchangeably to mean the same thing. Most people associate a diary with a special book that is closed with a padlock to keep your thoughts and feelings private. Journals are recorded entries that are often not as private, although you may choose to keep it so. A blog is often used to publicly share your thoughts on specific topics. Blogs have become so popular that even companies are using them to update people on changes in their industry or in their company. However, each is different and unique in its own right and they can be put to different uses. You may even choose to use one, two or all three.

A diary is often the most personal of the three. They are often arranged by date and have space for you to write what has happened over the course of the day. Many diarists often think of their diaries as a special friend that they can confide to. For example, Anne Frank named her diary "Kitty." She begins her entries with "Dear Kitty" so it as though she is writing to a dear friend that she can tell all of her secrets to. The naming of a diary has a unique psychological effect as it gives the writer a feeling of someone listening to his or her inner secrets and feelings.

The word diary itself is for the Latin word diarium or "daily allowance." A diary tends to be more focused on daily thoughts and events, while a journal can be written sporadically. The "page a day" diary is popular amongst young girls and are often given as gifts. However, the diary goes back hundreds of years and one of the first most popular diaries belonged to Samuel Pepys. Pepys is known for making the diary more personal, while it had been more of a business notation in the past. Several books have been published from diaries as well. It is these diaries that have given us great insight and knowledge into history from all parts of the world.

A journal is a diary in a sense. It can be used to document life events like a diary, but it is not necessarily a daily activity. There are also several different types of journals that a person may keep. There are travel journals to document your various travels across your state, country or the world. There are workout journals that help to keep track of the type of workout you do and make comments on it.

Journals have also become popular in schools. Teachers often give students a writing prompt to get them started in their journal writing. Each week the students may write from the prompt and then share the journal with their teacher. These are excellent because they get children to think creatively and to learn to put their thoughts and feelings down on paper. This is an important step in teaching children to express themselves and communicate effectively through the written word.

A blog is another form of diary or journal, but it is one that is digital and on the Internet. These are often referred to as online diaries/journals or personal blogs. They may document your day-to-day experiences or even social commentary. Many people use personal blogs as a way to keep in touch with friends and family, as well as to share with them their thoughts and feelings on certain subjects. You may choose to keep your blog personal or to share it with the world. By sharing it with the public, you can open the blog up to personal comments from those who view and read the blog. This is unique to the blog and many personal opinions are common throughout the world of blogging, some are kind and others may be quite blunt.

One of the first online diaries or blogs was Claudio Pinhaneza's "Open Diary." This was the first web site that was published in a diary format on a web page. This site was published in 1996 by the MIT Media Lab. Since, there were several different online diaries that popped up and now the web is full of them. There have also been several websites open up since then to allow people to have their own online journals and diaries. They are especially popular with teenagers and college students.

The blog has also changed the world in terms of marketing. In 2006, Entrepreneur magazine listed it as one of the top marketing tools of the year that can get your website noticed. Website promotion is a common hurdle in marketing an online business and because blogs are easy to set-up and use, they have become a popular way of sharing information and news with the online community.