Augmenting the answer to address your followup: parameters are any trainable variable in a model's definition. Model training is a process where you basically tweak the parameters in your model and then re-evaluate the model on a metric judging its quality. A lot of models consist of matrix multiplication, so if you are multiplying matrix A of size 2x2 with matrix B of size 2x2 and both matrices can we tweaked, then you've got 8 parameters, since you've got 8 numbers that can be tweaked