(יב) כַּבֵּ֥ד אֶת־אָבִ֖יךָ וְאֶת־אִמֶּ֑ךָ לְמַ֙עַן֙ יַאֲרִכ֣וּן יָמֶ֔יךָ עַ֚ל הָאֲדָמָ֔ה אֲשֶׁר־יהוה אֱלֹהֶ֖יךָ נֹתֵ֥ן לָֽךְ׃ {ס} (יג) לֹ֥֖א תִּֿרְצָ֖͏ֽח׃ {ס} לֹ֣֖א תִּֿנְאָ֑͏ֽף׃ {ס} לֹ֣֖א תִּֿגְנֹֽ֔ב׃ {ס} לֹֽא־תַעֲנֶ֥ה בְרֵעֲךָ֖ עֵ֥ד שָֽׁקֶר׃ {ס} (יד) לֹ֥א תַחְמֹ֖ד בֵּ֣ית רֵעֶ֑ךָ {ס} לֹֽא־תַחְמֹ֞ד אֵ֣שֶׁת רֵעֶ֗ךָ וְעַבְדּ֤וֹ וַאֲמָתוֹ֙ וְשׁוֹר֣וֹ וַחֲמֹר֔וֹ וְכֹ֖ל אֲשֶׁ֥ר לְרֵעֶֽךָ׃ {פ} (טו) וְכׇל־הָעָם֩ רֹאִ֨ים אֶת־הַקּוֹלֹ֜ת וְאֶת־הַלַּפִּידִ֗ם וְאֵת֙ ק֣וֹל הַשֹּׁפָ֔ר וְאֶת־הָהָ֖ר עָשֵׁ֑ן וַיַּ֤רְא הָעָם֙ וַיָּנֻ֔עוּ וַיַּֽעַמְד֖וּ מֵֽרָחֹֽק׃
(12) Honor your father and your mother, that you may long endure on the land that your God יהוה is assigning to you. (13) You shall not murder. You shall not commit adultery. You shall not steal. You shall not bear false witness against your neighbor. (14) You shall not covet your neighbor’s house: you shall not covet your neighbor’s wife, or male or female slave, or ox or ass, or anything that is your neighbor’s. (15) All the people witnessed the thunder and lightning, the blare of the horn and the mountain smoking; and when the people saw it, they fell back and stood at a distance.
(ג) לא תענה ברעך עד שקר. ובכלל זה הולך רכיל ומוציא שם רע
This includes spreading slander, Lashon Hara, speaking badly about people and something generally known as Motzi Shem Ra, defaming someone, ruining their reputation, and spreading damaging lies about others.
What's the difference between Rechilut, Lashon Hara, and Motzi Shem Ra?
Rabbi Yosef Karo, Kesef Mishneh, De'ot 7:1
One who "peddles gossip" (rechilut) refers to a person who says, "So and so did the following to you..." even though the information is not necessarily negative [but can nevertheless provoke arguments between parties]... since he carries the information around from one person to another, he is called a "peddler" [a traveling salesman of gossip].
Rambam, Mishneh Torah, De'ot 7:2
There is a sin that is much worse than rechilut, also included in the prohibition of "do not peddle gossip." This is known as lashon hara, or derogatory speech. This refers to someone who speaks in a derogatory manner about someone else--even though what he says is true. Someone who speaks lashon hara will say negative and derogatory things like, "So and so did the following..."
Rambam, Mishneh Torah, De'ot 7:2
[The previous case refers to someone who speaks negative information that is true.] Someone who speaks derogatory or harmful information about someone that is untrue is called slander (motzi shem ra).
במערבא אמרי לשון תליתאי קטיל תליתאי הורג למספרו ולמקבלו ולאומרו א"ר חמא ברבי חנינא מאי דכתיב (משלי יח, כא) מות וחיים ביד לשון וכי יש יד ללשון לומר לך מה יד ממיתה אף לשון ממיתה אי מה יד אינה ממיתה אלא בסמוך לה אף לשון אינה ממיתה אלא בסמוך לה
In the West, Eretz Yisrael, they say: Third speech, i.e., malicious speech about a third party, kills three people. It kills the one who speaks malicious speech, and the one who accepts the malicious speech when he hears it, and the one about whom the malicious speech is said. Rabbi Ḥama, son of Rabbi Ḥanina, says: What is the meaning of that which is written: “Death and life are in the hand of the tongue” (Proverbs 18:21). Does the tongue have a hand? Rather the verse comes to tell you that just as a hand can kill, so too a tongue can kill.