Short answer
Magento is the name commonly associated with a PHP-based ecommerce platform. Magento Open Source is the open-source edition; Adobe Commerce is a related commercial offering. The exact edition, release and deployment model determine features, support and system requirements.
Why the name can be confusing
An owner may say “our Magento site” without specifying which product or release it uses. That is fine in conversation and insufficient for an upgrade plan.
Adobe still offers Magento Open Source. Do not assume every Magento installation includes Adobe Commerce’s commercial features or support.
What you are operating
A commerce installation includes application code, extensions, PHP, a database and supporting services. Adobe’s system requirements list tested combinations and distinguish deployment models.
This matters when a security advisory arrives. Moving to the newest PHP version without checking the application’s compatibility can exchange one urgent problem for another. Staying on an unpatched version is not the answer either. Find the applicable security update and plan any required migration.
Magento versus WooCommerce
WooCommerce extends WordPress. Magento is a separate commerce platform. Both permit substantial customization; neither makes that customization free to maintain.
Compare the actual requirements: catalog structure, integrations, content workflow, implementation budget and the team available to run it. “More powerful” is not a useful buying criterion until someone says what power the business needs.
Before commissioning work, record the edition, exact application release, extensions, hosting model and PHP support status. That inventory is more useful than the platform name alone.