Blogging tools are designed to be easy to use. They generally don't provide all the advanced features of a complex content management system, but rather do one task — publishing a blog — very well. To this end, they can help you:
Create posts. Since the purpose of a blog is to be able to post new text or information to the site frequently, creating posts is usually quick and easy.
Upload or embed pictures and multimedia. Pretty much all blogs allow you to upload pictures to your posts. Some will also enable you to upload video and audio/mp3/podcasts. One significant note here is that most people do not have video that is in a "Web ready" format and often the video you have is just huge which means you risk spending a lot of money for the space to host the video and the bandwidth that enables people to view it. My general recommendation is to post your video on one of the video sites like YouTube or Vimeo and then use their embed feature to embed the video into your site. Quick, easy and no-cost.
Configure the appearance and layout. Tools vary widely in the degree to which they allow you to configure your blog, and the methods they offer to do this. Most blogs are built on themes — essentially a design template that can be installed and modified.
Display posts & comments to visitors. A blogging platform makes it easy for readers to view your posts and to add their comments.
Moderate. you will want to remove some of comments left by readers and you will eventually have to fight comment spam. Different platforms provide varying degrees of spam protection and moderation features to weed out unwanted contributions.
Publish RSS feeds. RSS feeds allow more tech-savvy users to subscribe to your blog and get headlines via myAOL, myYahoo, iGoogle or another RSS reader.
Find support. Not every blogging tool offers the same degree of support: while some offer personalized assistance, others have forums where you can find answers to your questions.
Host your blog. While some blogging software lives on your own server, others are hosted by the software provider or vendor. A great example of this is WordPress.com which is hosted by WordPress vs. WordPress.org which you download and install on your own server/hosting account.
These are some of the basic blogging features that pretty much all blogs provide.
Next time I will describe another set of features that you may not know about but will definitely be useful to maintain your blog.