If you regard someone or something as being a particular thing or as having a particular quality, you believe that they are that thing or have that quality.

If you regard something or someone with a feeling such as dislike or respect, you have that feeling about them.

If you regard someone in a certain way, you look at them in that way.

If you have regard for someone or something, you respect them and care about them. If you hold someone in high regard, you have a lot of respect for them.

Regards are greetings. You use regards in expressions such as best regards and with kind regards as a way of expressing friendly feelings towards someone, especially in a letter.

You can use as regards to indicate the subject that is being talked or written about.

You can use with regard to or in regard to to indicate the subject that is being talked or written about.

You can use in this regard or in that regard to refer back to something that you have just said.