Hi @fogx, this is a good question! Here’s what’s happening in to_tf_dataset: columns specifies the list of columns to be passed as the input to the model, and label_cols specifies the list of columns to be passed to Keras at the label. For most tasks (including sentiment analysis), you will usually only want one column to be passed here, in which case it doesn’t really matter what it’s called  because to_tf_dataset will only make the labels a dict when there are multiple label columns.
Sentiment analysis is an example of a ‘text classification’ task, so if you want a tutorial on that specifically, please take a look at this notebook or the colab link.