I see people here do not react to posts they read. While this is not required and not all posts are read by all people, but sometimes it is worth and even required to have a good reaction.
For example, if you read an answer to a question which you find it a good answer, or it is a good solution, I recommend to react and thump up, or like it! This way, when you look for a solution you can understand which answer is good which is better and which is not!
In simple words, lets rank solutions by suitable reactions and this way you will help other users who look for a solution to their questions.
Remarks:
- Many recommend respond instead of react, but I think you may not have the answer to a question, but if you tried a solution and found it useful, you can react
- Some forums like Hot Questions - Stack Exchange do not allow all people to react and one needs some reputation, have some scores to able to react, here you can react to solution if you understand them and you have tested them.