What’s the difference between RJ 45 and SFP+ ?

[Drama Lama]

In most network devices from high end switches, over low end routers, consoles, PCs and even some smart light bulbs   you‘ll find  RJ45 

but on some stuff you’ll find SFP+

 

RJ45

https://geizhals.de/asus-xg-c100c-90ig0440-mo0r00-a1614406.html

 

 

SFP+

https://geizhals.de/asus-xg-c100f-90ig0490-mo0r00-a2007502.html

 

 

to me these two network cards look almost the same besides the connector 

 

so

 

 

what does SFP+ have that RJ45 does not?

and

where and why is SFP+ mainly used?

 

 

I don’t know but could it be that SFP+ also supports optical cables?

 

[PineyCreek]

SFP+, specifically, is 10G, though some transceivers are dual-rate and can do 1G or 10G depending on your configuration.  SFP by itself will be a 1G transceiver.  They can be fiber or copper, though I would say the large majority of SFP+ transceivers will be fiber.  SFP and SFP+ are used in network gear that support them and are made for modularity and to avoid the limitations of having a fixed configuration in network gear.  The downside to having any modular network gear however is that you have to buy the transceivers for what you're doing, and those cost a bit on top of the gear.  That is the price you pay for the extra option of choice over a fixed configuration (like having just RJ45 connections).

 

Note:  If you're thinking about buying a transceiver for an SFP or SFP+ slot, make sure you're getting the right thing.  There's a number of factors to consider like single mode vs multimode (affects distance the light can travel...also price), compatible fiber types, and also what your network hardware can actually use.

 

Wikipedia's pretty good here:
https://en.wikipedia.org/wiki/Registered_jack

https://en.wikipedia.org/wiki/Registered_jack#Registered_jack_types

https://en.wikipedia.org/wiki/Small_form-factor_pluggable_transceiver