It's pretty much the grey area where walking and climbing meet. Easy scrambles are little more than walks, hard ones are effectively easy climbs. If you want a simple definition, scrambling starts at the point where you need to start using your hands to make progress. Simple eh? One definition you sometimes hear is that scrambling is 'climbing without ropes'. No, no, no... You won't need a rope on most easy scrambles, but depending on how experienced and competent you are, on a lot of the stuff at the harder end of the spectrum and on easier conditions on easier, but exposed routes, some people will definitely want a rope. Why do it then? Often the best and most inspirational routes up a mountain are scrambles - narrow ridges, dank chimneys, blocky, interesting buttresses. Easy scrambling is a taste of climbing, but without needing the technical knowledge and equipment.

There are a number of dedicated scrambling guides on the market which generally grade routes on a scale of 1 to 3 with an optional 3(S) to denote really serious stuff. Don't get too hung up on grades and remember that they're only a guide. Striding Edge on Helvellyn and Crib Goch on Snowdon are both classic grade ones, but the latter is much more exposed and potentially serious. Anyway, here's our guide to what they mean:
Grade 1 Don't need any specialist mountaineering skills so technically easy and can usually be done without a rope. This doesn't mean they're not dangerous, but they're the best starting point. In winter generally much more serious.
Grade 2 More serious. You'll need technical skills and probably a rope in anything other than ideal conditions - smaller holds and steeper ground are the norm. Not a good place for a novice.
Grade 3 Like grade 2, but with pitches of proper rock climbing where you'll need to know about technical ropework and how to protect yourself. Best done in dry conditions unless you're a confident, experienced climber. If you're a novice, don't even think about these.
3(S) used in some guides, denotes particularly serious 3s.

Andalucia province has a wealth of untapped scrambling potential. We shall embark on some of the best there is! Instruction will be given where necessary in the basic use of rope and gear for protection and safety. Guests should have a good head for heights and have some experience of hillwalking in the UK or Europe. Scrambles of grades 1, 2, 3 and 3S will be undertaken.

The scrambles include:
River gorge followed by mixed rock to a high plateau.
Long "alpine-type" ridge to a fine summit.
Long easy limestone ridge
High altitude ridge (similar to Aonach Eagach in Scotland)

Alpine Introduction courses - with an emphasis on training specifically for the Alps
Introduction to ropework for scramblers and beginner rock climbers
Animated Knots Link to interesting site about how to tie knots!