Open Source self hosted e-commerce platforms are popular because of the level of customisability they allow. Open source systems can be extended and changed to suit your requirements, which may in fact be entirely unique.
Magento is a very well know open source e-commerce platform that is used by some of the largest companies in the world. With one of the largest feature sets of any e-commerce platform, it can be customised to operate stores handling a large number of transactions and with very complex workflows. For many of our clients, Magento provides a lot of functionality that will never be used. With such a great number of features, users are very often daunted by what they consider over-complicated. Our recommendation is generally to only consider using Magento if you have a very large inventory, complex requirements, or experience with it already.
Woocommerce is a plugin that can be installed into a WordPress site. We do not recommend developing an e-commerce site using Wordpress to run a serious e-commerce business unless there are justifiable circumstances (e.g. a well established wordpress site already exists). Whilst many people do run their stores using this setup, it is not well advised as a long term solution. Our opinion as a digital agency is that there are far more suitable platforms developed for this purpose.

