The likelihood function returns a probability. Specifically it tells you, for some parametric model, how the joint probability of the data in your data set varies as a function of changing the parameters in the model.
If that sentence doesn't make sense, then it's helpful to just write out the likelihood function. You will notice that that it is in fact just the joint probability density of your model.
The only thing that makes it a "likelihood function" is that you fix the data and vary the parameters, whereas normally probability is a function of the data.
I’m native speaker and I thought they were the same. Still unsure of the difference. I guess I need to study this.
The likelihood function returns a probability. Specifically it tells you, for some parametric model, how the joint probability of the data in your data set varies as a function of changing the parameters in the model.
If that sentence doesn't make sense, then it's helpful to just write out the likelihood function. You will notice that that it is in fact just the joint probability density of your model.
The only thing that makes it a "likelihood function" is that you fix the data and vary the parameters, whereas normally probability is a function of the data.