Answer:
repeat-y ................ ..
The answer is mobile communication, this consists of emails, texts, and parts of social media (Ex. DM's)
Personal information intentionally put on a secure website
Talking about models, validation is the process by the model is corroborated and its outputs are compared with experimental results. From validation, it can be seen how quantitative and qualitative accurate the model is, and it can be confirmed model fidelity to the real world.