Hi, In this video we’re going to look at screen resolution versus our actual pixel size.  

So this can be a little confusing when you are starting.  You’re thinking, great, - I’m going to do a mockup for an iPhone 6, and you go into photoshop, and you go, -  here are the dimensions - you google it, and it says this pixel width, by this pixel height, and you decide, - alright,  I’m going to make that, so I’m going to go into photoshop. I’m going to make a new document.  It’s going to be 750 x 1334, and you make it, and you end up with this size here,  Now this isn’t the true size it’s going to be.  Let’s look back at the website here, and we’ll see that  it’s the CSS width that we really need to observe when we are designing for mobile.  Because we all know that mobile phones, apart from a couple of them, are all very similar in size, but what will happen is this pixel ratio here, you can see when it is 1 to 1 that it is,  whatever the physical size it is, it’s the actual size of the screen here. Theres no real density, and if  you’ve seen an old iPhone 3, you’ll  notice that the graphics aren’t great, but it’s the same physical size as an iPhone 6.  But what happens is, when you get this denser pixel ratio - the same physical size, we see it doubles here, - the actual pixels get a lot bigger, but the actual size of the phone is exactly  the same, you’ll notice say this LG G4,  this one here has a pixel ratio of 4, so it’s quite a small phone - the same sort of size as the iPhone 6, but you can see it’s hugely big in terms of it’s physical width, but if we have a look at it here in comparison with each other, they are actually not that different, slightly bigger,  the iPhone 6 is slightly bigger, but not a huge big jump, as in this indication here, so it can be quite confusing when you’re new. The basics are, - is that when you are designing in photoshop, designing for  exact physical size, we’ll give you the best representation of the actual phone, rather than following these physical pixel widths over on this side here.