can someone tell me what is the diffrence between this 2 relays?

Other Hardware Motors, Mechanics, Power and CNC
1

http://www.aliexpress.com/item/2-5V-30A-1-Channel-Relay-Module-Optocoupler-H-L-Level-Triger-in-selling/32342340182.html - using SLA-05VDC-sl-c

http://www.aliexpress.com/item/1PCS-30A-250V-Relay-Module-High-side-Driver-SLA-05VDC-SL-A-FZ0885/32454140486.html - using SLA-05VDC-sl-a

2

There are obviously many differences, but one has an optocoupler.

3

I really thought that the main difference is the relay itself, SLA-05VDC-sl-c vs SLA-05VDC-sl-a.
I looked at the data sheet but I still didn't get, (I'm sorry that I didn't mention it but I'm a noob :o ).

So what is the difference between also the relay, and what would you recommend more.

4

What do you want the relay to do? What are the other constraints on your project?

5

Basically I want to do the following: ESP8266 - Flash NodeMCU, write lua script, and control a water heater
But in my way.

6

anyone?