Constitutional rights are fairly easily defined though they don’t exist for all people and may not be the same in different areas of the world. These rights are those guaranteed to people and explicitly stated in a government's constitution, which sets forth laws of the region. There are many countries that have implicit constitutional rights instead, but some countries make a statement of rights to which citizens and possibly others in the country are entitled.
A familiar example of constitutional rights is the United States of America's constitution, which devotes its first ten amendments to explicitly defining the rights of its people. The US constitution later was enhanced by the addition of amendments that expand certain rights. These include the right for more people to vote or amendments that protect people from undue discrimination by the government or others due to things such as race or gender.
The basic constitutional rights afforded people in the first ten amendments or the Bill of Rights include the right to an expedient trial and deliberation by a jury of peers. They exclude illegal search and seizure of property.
People in the US have the ability to exercise free speech, free press, free choice of religion, and they have right to bear arms. Other rights like the right not to self incriminate and to freely assemble exist too. Provided the constitution remains unchanged, the right to any of these things is guaranteed by law, with some exceptions, which are now more limited than was once true.
The way person or citizen is defined has changed over time. Women, slaves and Native Americans lacked full constitutional rights for many years. The extent to which constitutional rights have an impact depends on the group of population defined as citizens. If this a small group, then it really doesn’t matter how expansive and liberal a constitution seems in granting rights. A constitution could be a document of extraordinary discrimination despite appearing to offer a lot of rights to “citizens” or another defined group.
People might also lose rights granted by a constitution, under some circumstances. This could occur if they commit crimes of a certain nature. Again, it all depends on how a constitution defines “persons” who are allowed rights. Similarly, rights are usually granted only to citizens, but they might also apply to legal residents or visitors.
In essence, the way a state defines persons determines who has protected, stated rights under the law, and each country could determine exactly what constitutional rights exist for its defined set of “persons.” Many of these rights are the same and there also may be a sense of human rights that underlies any specific documents suggesting constitutional rights. Not all governments explicitly set forth a series of rights in a constitution, but there can be implicit understanding that citizenry or anyone in a country is entitled to certain things.