1N4148 signal Diode

Charactiristics 1N4148 diode
Maximum Recurrent Peak Reverse Voltage - 100 V
Maximum Average Forward Output Current - 0.15 A
Maximum Forward Voltage Drop per element at 1.0A DC - 1 V
Maximum reverse recovery time - 4 ns
Typical Junction Capacitance 4 pF
Package - DO-35
Weight 0.13 grams
Operating and Storage Temperature Range -65...+150 °C

Polarity and Pinout
1N4148 diode has a cathode (-) and anode (+). In the schematic symbol, the tip of the triangle with the line on top of it is the cathode. The cathode is marked on the body of a diode by a band.
Diode polarity Current can flow from the anode to the cathode only and never from the cathode to the anode - 1N4148 diode is like a one way valve.
You can replace 1N4148 with 1N4448WS, 1N4448W, 1N4448, 1N4148WS, 1N4148W