Silver steel and high carbon steel are more or less the same thing - these days chromium is added rather than silver, hence the term 'chrome steel'. This is done to reduce or eliminate polishing times. All razors are made from carbon steel (except of course stainless steel blades, stainless steel is defined as an iron-carbon alloy with a minimum of 10.5% chromium content. The terms are bandied about quite a bit - let's face it 'silver steel' sounds quite cool, doesn't it? In the past makers also used terms such as 'magnetised' steel (though what this was is anyone's guess, being a pure advertising ploy!) 'India' steel (?????) and even 'Manganese' steel (all carbon steel contains manganese).

Hope this helps!