Advantages
Free
Joomla! is an open-source platform, allowing you to freely use code without worrying about licensing fees. Joomla also provides hundreds of free extensions templates.
eCommerce Supporting
Joomla users are able to manager their content and their online store in the same place instead of using multiple platforms. Joomla supports some eCommerce components that are great for creating shopping stores such as: VirtueMart, JoomShopping, K2Store...
Easy to Install
Joomla installation takes only a few minutes to complete. You can easily download and install your Joomla webpage.
PHP Scripts
Joomla uses complete PHP scripting - the most common web development language. The compatibility issues should be limited when using the framework of Joomla.
Extensions Availability
A Joomla’s plugin or component can provide a various of functionalities that you do not need to install to much plugins/components in building your website.
Adaptability and Flexibility
You can use Joomla for your small business and expand it when needed. With some HTML knowledge, you are able to maintain your Joomla site. You don’t have to be a developer to use it.
Active Community
Joomla has a large user community where you can get advice, tips, tricks tutorials to assist you in building your website.
SEO capabilities
It’s no longer necessary to search for third party plugins and achieving decent ranking on search engines such as Google will no longer be an issue.
Disadvantages
Slightly Complex
Joomla is quite complex that makes it difficult to incorporate your own custom design without developer experience. However, using it for content management doesn’t take an extensive amount of time to learn.
Compatibility
Joomla has compatibility problems when you simultaneously installed several modules, extensions and plugins.
Based on the pros and cons of Joomla, you can see that Joomla offers some advanced tools for building a great site. Depend on the website requirements, what do you want to dispatch and your skills, you should choose the right open source content management system for your website.