user91708: What does the -server option do in bitcoin node? https://en.bitcoin.it/wiki/Running_Bitcoin says 'Accept command line and JSON-RPC commands'. However I can't see any difference whatsoever. In both cases I'm able to curl my request as well as use the cli. 

user92327: As stated by the help, 
  -server
       Accept command line and JSON-RPC commands

You may however also have to check if this configuration parameter has been enabled by your local configuration, usually a file called bitcoin.conf, unless configured using the -conf parameter to bitcoind.
On linux builds, this should default to ~/.bitcoin/bitcoin.conf, on Mac OS X ~/Library/Application\ Support/Bitcoin/bitcoin.conf
In this file, you can explicitly configure the server as off using the server configuration parameter.
server=0

You can alternatively pass a parameter as 1 (enabled) or 0 (disabled)
bitcoind -server=0

You should not be able to access your server assuming this has been toggled to 0.
The headless daemon bitcoind has the JSON-RPC API enabled by default, the GUI bitcoin-qt has it disabled by default.  

91708: <p>What does the -server option do in bitcoin node? <a href="https://en.bitcoin.it/wiki/Running_Bitcoin" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Running_Bitcoin</a> says 'Accept command line and JSON-RPC commands'. However I can't see any difference whatsoever. In both cases I'm able to curl my request as well as use the cli. </p>
 92327: <p>As stated by the help, </p>

<pre><code>  -server
       Accept command line and JSON-RPC commands
</code></pre>

<p>You may however also have to check if this configuration parameter has been enabled by your local configuration, usually a file called bitcoin.conf, unless configured using the -conf parameter to bitcoind.</p>

<p>On linux builds, this should default to <code>~/.bitcoin/bitcoin.conf</code>, on Mac OS X <code>~/Library/Application\ Support/Bitcoin/bitcoin.conf</code></p>

<p>In this file, you can explicitly configure the server as off using the server configuration parameter.</p>

<pre><code>server=0
</code></pre>

<p>You can alternatively pass a parameter as 1 (enabled) or 0 (disabled)</p>

<pre><code>bitcoind -server=0
</code></pre>

<p>You should not be able to access your server assuming this has been toggled to 0.</p>

<p>The headless daemon bitcoind has the JSON-RPC API enabled by default, the GUI bitcoin-qt has it disabled by default.  </p>
