In standard casino games like blackjack, you play strictly against a cold, mathematical algorithm or a heavily regulated dealer following rigid rules.

These physical and behavioral leaks are known universally in the poker world as "tells."
Reading Body Language at the Table
The human body is incredibly terrible at hiding massive spikes in adrenaline caused by extreme stress or intense excitement.

Conversely, a player holding absolute garbage cards will generally appear relaxed, bored, or artificially focused on an irrelevant distraction.
Acting overly confident or talkative during a hand usually indicates a massive bluffA player who suddenly goes completely silent and rigid is incredibly dangerousAlways watch a player's eyes the exact moment the flop hits the felt Analyzing How Opponents Bet
While physical twitches are dramatic and fun to spot, the absolute most reliable tell in all of poker is a player's actual betting pattern.

A long, agonizing pause followed by a massive all-in shove is almost always the incredibly strong "nuts" trying to extract maximum value.
How to Filter the Noise
If a player always shakes uncontrollably because they drank six espressos, their trembling hands are entirely meaningless regarding their card strength.

A professional will intentionally sigh and act weak specifically to induce you into calling their massive value bet.
Observed TellCommon Meaning (Amateurs)Action RequiredShaking / Trembling HandsMassive adrenaline, monster handFold all marginal hands instantlyStaring aggressively at youAttempting to intimidate, weak handConsider a re-raise or hero call
Spend your time at the table actively studying your opponents rather than staring mindlessly at your phone between hands.