Is withholding information the same as Lying? In this question, there would be no inquiry to the part being withheld . . . It is simply left out of the conversation.

That depends on the circumstances.  Sometimes it's irrelevant drivel that should be omitted to keep the conversation flowing or on track.  Sometimes it's private stuff that's nobody's business.

But sometimes people leave out important information to conceal or manipulate.  I use motive when determining if it's a lie of omission or tact.

I am with Joy. I think it really depends on the information and why it is being withheld. My family tends to hold back medical news until we have more information. There is no need to worry people unnecessarily.

Plosible deniability.

To me, lying refers to something where a question is asked and false information is provided OR . . . incomplete information is provided to alter the outcome or overall information purposefully and with ill intent.

It also goes to relevancy of the topic . . .

"What did you do today?"

"Pretty much the same old thing." . . . . Pretty much gives license to not Exactly the same old thing . . . Could be anything from rescuing a kitten from a well, to spending $200 at a strip club . . .

"What falls under Pretty Much?" . . .

"Oh nothing really . . . I found a kitten stuck in a well . . . No biggy."

I would make a distinction between social vs legal situations.

The italics are a summary from Wikipedia---note the requirement to tell the whole truth.

In legal situations, sworn testimony is evidence given by a witness who has made a commitment to tell the truth. If the witness is later found to have lied whilst bound by the commitment, they can often be charged with the crime of perjury. The types of commitment can include oaths, affirmations and promises which are explained in more detail below. The exact wording of the commitments vary from country to country.  In the USA, the form of the oath is "Do you solemnly (swear/affirm) that you will tell the truth, the whole truth, and nothing but the truth, (so help you God/under pains and penalties of perjury)

As some have indicated above, questions that are commonly part of social exchange (which frequently are part of the stoke economy) have a wide range of acceptable answers and they are not to be construed as given under oath.

So---"No."

There is a clear distinct difference between male and female brains. My husband likes to tease me saying "Yin I don't need to hear that the fly landed on the wall when you are reeling a story." He is simple, likes it to get straight to the point so he can fix or handle. Me on the other hand seem to find myself asking "why didn't you tell me that part!" Or "when we're you gonna tell me this!" Meaning he NEEDS to tell me the fly landed on the wall sometimes! Lol! So to answer your question, male and female brains put aside, I agree with Joy and everyone else.... It is the intend behind the ommision.