user58413: I have previously connected 5V 10A relay switches to my Arduino.
But for my new project I need to use a 5V 30A relay switch with my Arduino.
In 10A relay switches, we make connection with Arduino using GND, VCC and IN.
But for 30A switches, there are DC+, DC-, IN.
My question is that, how do I connect my Arduino to the relay using these pins?

user58355: From the Amazon page you linked to: 

1 dc+ : Dc power supply positive pole
  2 dc- :Dc power supply negative pole (i.e. ground)

Arduino:
VCC: positive DC power supply
GND: ground
technically, VCC = the voltage at the collector of a transistor, these days it's used as shorthand for the positive output pin of an IC.

58413: <p>I have previously connected <a href="https://www.amazon.in/dp/B01HXJDBII/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=cd818f9c-142a-4b42-ad2c-f0421857aaf5&amp;pf_rd_s=lpo-top-stripe&amp;pf_rd_t=201&amp;pf_rd_i=B00C59NOHK&amp;pf_rd_m=A1VBAL9TL5WCBF&amp;pf_rd_r=MJP2SHRW2PN89Y5J5V18&amp;pf_rd_r=MJP2SHRW2PN89Y5J5V18&amp;pf_rd_p=cd818f9c-142a-4b42-ad2c-f0421857aaf5" rel="nofollow noreferrer">5V 10A relay switches</a> to my Arduino.</p>

<p>But for my new project I need to use a <a href="https://www.amazon.in/xcluma-1-Channel-Module-Optocoupler-Trigger/dp/B072THSX9Q/ref=sr_1_1?keywords=5v%2030a&amp;qid=1564212590&amp;s=industrial&amp;sr=1-1" rel="nofollow noreferrer">5V 30A relay switch</a> with my Arduino.</p>

<p>In 10A relay switches, we make connection with Arduino using GND, VCC and IN.</p>

<p>But for 30A switches, there are DC+, DC-, IN.</p>

<p>My question is that, how do I connect my Arduino to the relay using these pins?</p>
 58355: <p>From the Amazon page you linked to: </p>

<blockquote>
  <p>1 dc+ : Dc power supply positive pole<br>
  2 dc- :Dc power supply negative pole (i.e. ground)</p>
</blockquote>

<p>Arduino:<br>
VCC: positive DC power supply<br>
GND: ground</p>

<p><a href="https://en.wikipedia.org/wiki/IC_power-supply_pin" rel="nofollow noreferrer">technically</a>, VCC = the voltage at the collector of a transistor, these days it's used as shorthand for the positive output pin of an IC.</p>
