1N4148TR is a small signal diode from On Semiconductor, rated for 100V reverse voltage and 200mA forward current. It comes in a through-hole DO-35 package.
The 1N4148TA is a small signal switching diode from onsemi, rated for 100V repetitive reverse voltage and 200mA average rectified forward current. It comes in a DO-204AH (DO-35) through-hole package.