When we talk about these two concepts then both are considered significantly important in our regular social interactions as both these revolve around human behavior and are frequently used interchangeably. But still the meanings of these two terms are totally different so you should not mix these words as the same.

First of all, if we talk about etiquette then it can be defined as a code of conduct or set of rules prescribed by society for having better human interactions. And when we talk about manners then you can simply understand it as behaviour of humans towards one anothers that reflects their attitudes. Here the major difference which can be counted in both these terms is that the criteria of etiquettes could be changed with the changes in social norms and customs but manners will remain unchanged across various different communities.

In etiquettes, here you are going to find a well designed structure within which manners of good level can flourish. This means you can say it as good manners are certainly required if someone wants to follow the proper etiquettes. So, etiquette basically means the rules which should be followed by someone while talking to the other one. In many cultures, you may have seen that people usually shake their hands when they first meet with one another while in many other cultures, shaking hands is not regarded well. And if we talk about manners, then saying a few good words like ‘please’ or ‘thank you’ whenever required and never interrupting people when they are talking, all these kinds of good behaviors are counted under the universal courtesies. https://www.youtube.com/watch?v=ouVtuf1fDmE&t=14s