Building sites over the web is a very popular practice these days and site owners use them in order to share a lot of information with their visitors. One of the main issues is that the content they post is not always related to the same topic and this is one of the things that may backfire, since they do not build their sites according to the content.
Even though some people find a niche and they try to do all that they can in order to make the most of it, there are many things that can happen along the way and there are other topics that can become more important. If you are running such a site, you have to know how you should structure it in order to handle the content better for the users.
A domain is just like a home. If you would put all the people along with all their belongings in the same room, they would not have any boundaries and everything would be mixed up together. If you want to keep things organized, you have to put every person in their own room and they can make use of the space at hand in any way they see fit.
A sub-domain is viewed by search engines as a site on its own
If you want to organize your domain so things do not get mixed up together, you can put every topic you want to address in their own sub-domain and thus everything will be in order. All the content you want to publish related to that topic can be placed in other directories and users will have a very easy time finding what they are looking for.
One of the arguments people get in is whether they should use sub-domains for every topic or if directories will be enough. Even if the latter will help organize things, a sub-domain is viewed by search engines as a site on its own so optimizing it will be easier. Search engine optimization is one of the most important things you should focus on.
Life over the web can be full of things you are not prepared for and search engines can also penalize you due to the updates on their algorithms. If you would structure your content in an organized way, the penalties you incur will not affect the entire domain and all its sub-domains, it would focus on the part of the site that did something wrong.
Another option you have at hand is to use different domains altogether in order to structure your content. Instead of putting everything under the same roof, you can use a different site for every topic you want to address and thus you will eliminate every worry you may have on your mind.
You are not the only one who is facing this dilemma and there are some people who can give you a much better point of view on things. If you want to read their thoughts on the issue, you can join the discussion you will find on the forum of Webmaster World.