Question is plugging ethernet cable into ethernet port the same as plugging into RJ45 Gigabit Ethernet Adapter

[minni]

Sorry I'm not savvy at tech jargon. So:

If i plug my ethernet cable into an RJ45 Gigabit Ethernet Adapter (which is plugged into a USB-C port),
...does that have the same effect as plugging my ethernet cable into a built-in ethernet-port?
Is the latter more stable, than an adapter?

BTW, if they'd call it a "USB-C to Ethernet adapter" - i might understand that it supports my ethernet cable.
But instead they call it a USB-C to RJ45 Gigabit Ethernet Adapter. So is that the same?

 

[Aeacus]

.does that have the same effect as plugging my ethernet cable into a built-in ethernet-port?

Generally: Yes.

But there can be limitations. Read below.

Is the latter more stable, than an adapter?

Stability can be defined many ways.

E.g connection stability. For this, it is equal between both since both are wired connections and not wireless, like wi-fi, which can have stability issues.
But for e.g overall stability. Well, using adapter gives one more point of failure and it may be less reliable (adapter can malfunction).

BTW, if they'd call it a "USB-C to Ethernet adapter" - i might understand that it supports my ethernet cable.
But instead they call it a USB-C to RJ45 Gigabit Ethernet Adapter. So is that the same?

Latter includes 2 specific limitations.

1. RJ45 - what type of connector it has on the other end.
2. Gigabit - max bandwidth of the adapter. 1G.

For Ethernet, there are actually far more connectors than the common RJ45. So, when it is defined in the adapter name, you know off the bat if you get the right one.
Further reading: https://www.cbtnuggets.com/blog/tec...ng-essentials-connectors-and-cable-management

If it wouldn't state the connector type, and you buy one named just "USB-C to Ethernet adaper", you could end up with this:

Bigger version of the image: https://www.lindy.co.uk/images/100m-fibre-optic-usb-3-2-type-c-extender-p13383-16136_image.jpg

Btw that one is USB-C to LC (fiber optic) 10G Ethernet adapter.

And for bandwidth, there are limitations as well. E.g when your ISP provides you 2.5G internet but you only buy Gigabit adapter, then you're limited to 1G, or 1000 Mbps speeds, rather than 2500 Mbps provided by ISP.

Having more info on the product name is always better than having less info.