Anode and cathode are two fundamental concepts in electrochemistry and electronics. They are commonly encountered in batteries, electrolysis, and various electronic devices. Here are the key differences between anode and cathode:

1. Definition:

   • Anode: The anode is the electrode where oxidation (loss of electrons) occurs during an electrochemical reaction. It is positively charged in an electrolytic cell and negatively charged in a galvanic cell or battery.
   • Cathode: The cathode is the electrode where reduction (gain of electrons) occurs during an electrochemical reaction. It is negatively charged in an electrolytic cell and positively charged in a galvanic cell or battery.

2. Charge:

   • Anode: The anode is positively charged in an electrolytic cell and negatively charged in a galvanic cell or battery.
   • Cathode: The cathode is negatively charged in an electrolytic cell and positively charged in a galvanic cell or battery.

3. Electron Flow:

   • Anode: Electrons flow away from the anode during oxidation. In an external circuit, current flows from the anode to the cathode.
   • Cathode: Electrons flow toward the cathode during reduction. In an external circuit, current flows from the cathode to the anode.

4. Electrolysis:

   • Anode: In an electrolytic cell, the anode is the electrode connected to the positive terminal of the power source. It attracts negatively charged ions (anions) from the electrolyte and undergoes oxidation.
   • Cathode: In an electrolytic cell, the cathode is the electrode connected to the negative terminal of the power source. It attracts positively charged ions (cations) from the electrolyte and undergoes reduction.

5. Galvanic Cell or Battery:

   • Anode: In a galvanic cell or battery, the anode is the electrode where oxidation occurs spontaneously, producing electrons and generating electric current.
   • Cathode: In a galvanic cell or battery, the cathode is the electrode where reduction occurs spontaneously, consuming electrons and completing the electric circuit.

6. Polarity:

   • Anode: In electronic devices like diodes and vacuum tubes, the anode is typically the positive terminal.
   • Cathode: In electronic devices like diodes and vacuum tubes, the cathode is typically the negative terminal.

In summary, the anode and cathode are electrodes with opposite charges and roles in electrochemical reactions. The anode undergoes oxidation and is positively charged in electrolytic cells, while the cathode undergoes reduction and is negatively charged in electrolytic cells. In galvanic cells or batteries, the anode produces electrons, while the cathode consumes electrons to complete the circuit.