Bekhorot 50: words to know

פִּדְיוֹן הַבֵּן (pidyon haben): Redemption of the firstborn son from a priest. The Gemara calculates the exact coin weight required to perform this redemption.
כֶּסֶף צוֹרִי (kesef tzori): High-value silver coinage of Tyre required by Torah law. Rav Asi states that unspecified monetary sums in the Torah refer to Tyrian currency.
כֶּסֶף מְדִינָה (kesef medina): Provincial currency worth less than standard biblical coins. The Gemara explains that rabbinic fines and payments are evaluated in this lower currency.
וּכְלָלָא הוּא (ukhelala hu): And is it an established, universal rule?. The Gemara uses this rhetorical challenge to question Rav Asi's general rule about coins.
שָׁוֶה פְּרוּטָה (shaveh peruta): The value of a peruta, the minimal halakhic sum. Cited in Shmuel's teaching that consecrated property can be redeemed using anything of this minimal value.