The core idea is following “Freedom of speech is a principle that supports the freedom of an individual or a community to articulate their opinions and ideas without fear of retaliation, censorship, or legal sanction.”
This principle’s main focus is to allow criticism of government and other actors of power.
The concept is really simple and fair. The tricky part comes from other human rights, The Rule of Law principle and Rechtsstaat (State of law), which mean that the law is the same and equal for everyone, and that the state is fair and upholds the rights of the citizens equally.
Now you might wonder why would this be tricky? Well according to state of law and the rule of law principles you cannot have a right that allows an infringement of another right. Meaning you cannot walk into someones home or other private property and claim you are exercising your right to freedom of movement. Or steal a book and claim your right to education. So this means that Freedom of speech is limited by other human rights, like for example the right to life, the right to not be discriminated against or the right to privacy. Thus Freedom of speech does not protect speech that breaks other rights. You cannot make a true threat for someones life or reveal someones personal information without legal sanctions and I believe everyone sees this as a good thing.
Main point and focus of Freedom of Speech has always been to prevent censorship by the state, for example deny the person’s ability in advance to post or write in a news paper at all or about a certain subject that might be disadvantageous to the government.
Now in modern digital era, many people falsely believe that freedom of speech allows them to say anything they want and that people could not react negatively to them. This is totally incorrect, people’s right to freedom of speech allows people to equally criticize the speaker for his speech. You are not entitled to have an audience to your speech. People are not forced to hear you or participate in someones conversation. Opinions don’t need to be automatically considered valid, but people as person’s do in regard of the law. Respect is earned and not given.
Only thing I consider flawed in this system is the rare cases of 100% facts that do interfere with other human rights. These cases are rare and 98% of them can even be re-phrased to not offend other human rights, but some cases require speech that will infringe other rights. Now in these cases I personally would see fit to extend the Freedom of speech rights, but only for if the whole argument made is 100% correct and not a single piece of misinformation or even malicious false analogies are present on the speech. This way we can civilly discuss hard matters and keep the speech respectful and facts based without breaching the idea of “State of law” and the rule of law principle.
if anything here was news to you, I suggest reading https://en.wikipedia.org/wiki/Freedom_of_speech and continuing from there to further ponder the use and limits of free speech.