"Paltering" refers to the use of truthful statements to create an overall untruthful narrative.
This differs from a "lie of omission" in that such a lie generally means navigating around things you don't want to share or declining to correct an incorrect impression, while a palter focuses on what you do share: truths that add up to a misleading overall impression, strategically offered in order to create that impression.
This approach is commonly used by politicians and other public figures who might be keen to avoid adding outright lies to their recorded ledger, but it's also an everyday tactic people use in lieu of lies on a semi-regular basis (based on what little research is available on this, at least).
If you're looking to sell your house, for instance, and you know the basement sometimes floods when it rains, and a potential buyer asks you about the house’s history of flooding, you might say, "The house has passed all recent inspections, and we've never experienced any property damage from flooding."
This statement might be literally true in that the house has passed all recent inspections and no property damage has been noted from the flooding that has occurred, but this doesn't mean flooding never occurs and that property damage couldn't happen as a result. The two truths shared may create an impression of a third truth in the mind of the would-be buyer, but that impression is false.
It's been theorized that part of why this tendency is so common is that we often have competing interests in our social interactions: we want to be perceived as trustworthy, but we also want to—for instance—sell our house, or we want to win an upcoming election.
Thus, we avoid outright lying, which allows us to feel like trustworthy people (maybe shifting the perceptual blame onto the rube who bought our flood-prone home because they failed to ask better questions) while still presenting information in such a way that the person we hope to misinform is, indeed, misinformed.
Lying by commission—which is telling an outright falsehood, rather than lying by omitting relevant information—is also incredibly common: one study from 1996 suggested that most people lie at least once or twice a day (though this study used self-reported data, so the true figure could be much higher).
But paltering is worth understanding as a separate concept because folks who palter are more likely to be able to internally justify their mistruth because of how it's presented, and may get away with spreading such mistruths because paltering is often quite effective and trickier to catch than an outright lie (in some contexts at least).
Palters are often considered to be higher-risk tactics than outright lies, though, because the people telling them are essentially putting their own reputations up as a bet that the other person will buy into their narrative without questioning it.
Studies on paltering within negotiations have found that those who use this approach and are then found out are considered to be less-trustworthy moving forward, taking a more substantial long-term hit compared to those who suffer comparably short-term reputational damage from telling some kind of fib.