This is quite a basic question.
freedom is an abstract noun: Freedom is good. Freedom of speech is even better.
In English, abstract nouns do not take articles:
- Wealth is a relative concept.
- Freedom has many tentacles. Freedom of movement was restricted in that year.
- Love has many splendors.
This includes adding something to the abstract noun with an of:
- Freedom of movement is essential to well being.
- Love of nature is not the same for everyone.
Unless it is qualified, no article is used.
- The wheelchair gives him the freedom to go out on his own.
freedom is qualified there. It is the specific freedom to go out.
- Tracksuits are designed to give you freedom of movement.
freedom is being used as an abstract noun.
abstract nouns with and without articles