Confusion with WiFi speeds- can someone clarify please? ...

[m654321]

NIC stands for Network Interface Card 

I'll try to keep it semi-brief as not to complicate but... Both 1 and 2 numbers are separate from each other but do factor together...
You have the speed between your PC's and Router how much info the pc can receive from the router and then the ISP speed; the pipeline from your router to the ISP, to where ever on the internet and back...

For 1 Focusing on the LAN (Local Area Network) Router to Laptop:
The 37.5MB/s you see is the current speed the WiFi is running, the 300MB/s is the max speed of the card.. The 300MB/s relates to a "N" wifi (802.11n); there are limitation in which 300MB/s will be hard to achieve - Although a max 150MB/s is more realistic; I see 144MB/s speed on my box...
With that in mind... "G" (802.11g) speeds are up to 54MB/s..
If you're router is a "G" router and your Laptop WiFi NIC is "N".. The Fastest you'll see is "G" on any device... If Router is an "N" and Laptop is "G"... "G" will be the highest speed available on that device.. The fastest you'll be is the slowest protocol in the given equation..
-- Matching Router and NIC's for optimum performance, not only to the internet but between PC's on the same LAN .

All that being said - For WiFi that's the ideal situation, close proximity and direct line of site..
- the farther away and more walls the signal passes through can diminish the speed.
If the router is on the 2nd floor and the PC is in the basement that signal has to pass through the walls and floor therefore performance takes a hit...

For the 2nd part (2) Focuses on the WAN; the speedtest should roughly equate to the providers speed, again in ideal situations and "up to".. If you have an advertised  30Mb/s download and the speedtest shows 28MB/s I'd say you're ok... If same 30 and seeing 10MB/s, you may want to note and compare other readings at different times; as there are other factors that come into play.. Time of day, service outages/upgrades, type of service/throttling or even weather - everything to and from the internet and ISP and the route to your router.. You may see different speeds on Saturday at 2:00pm vs. Wednesday at 1:00am, Saturday more ISP users accessing than on Wednesday...

Hope I didn't over explain  ;D

@firenice03
I must say that these different connection speeds we discussed  do seem more complicated than I first though
I think sometimes it's good to over-explain, that is assume I have  no knowledge and then I've got all the bits I need & can just skim over what's known already.
I think at one stage you mixed up MB and Mb which can be a bit confusing - my ISP did this in their advertising and drew their attention to this - they were advertising "up to 17Mb" instead of 17MB..!  17Mb/s isn't a very good deal :-(

Many thanks again -  you're a champion !

Mike