I'm trying to create ML models dealing with big datasets. My question is more related to the preprocessing of these big datasets. In this sense, I'd like to know what are the differences between doing the preprocessing with Dataprep, Dataproc or Tensorflow.
Any help would be appreciated.
Those are 3 different things, you can't really compare them.
Dataprep - data service for visually exploring, cleaning, and preparing structured and unstructured data for analysis
In other words, if you have a large training data and you want to clean it up, visualize etc. google dataprep enables you to do that easily.
Cloud Dataproc is a fast, easy-to-use, fully-managed cloud service for running Apache Spark and Apache Hadoop clusters in a simpler, more cost-efficient way.
Within the context of your question, after you cleanup your data and it is ready to feed into your ML algorithm, you can use Cloud Dataproc to distribute it across multiple nodes and process it much faster. In some machine learning algorithms the disk read speed might be a bottleneck so it could greatly improve your machine learning algorithms running time.
Finally Tensorflow:
TensorFlow™ is an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them.
So after your data is ready to process; you can use Tensorflow to implement machine learning algorithms. Tensorflow is a python library so it is relatively easy to pick up. Tensorflow also enables to run your algorithms on GPU instead of CPU and (recently) also on Google Cloud TPUs(hardware made specifically for machine learning, even better performance than GPUs).