What on earth is "shortening"?

I've been experimenting with cookie recipes and trying to copy and paste over a year worth of diary entries into a blog site (so it can be searchable and I can link the evolution of my more useful ideas). The diary is up to four months dealt with and many to go. It's a pain to do but I love how it looks and I think it will be more useful to me when it's done (plus I kinda like the geek stuff). The cookies are more reservedly successful.

I mean, does anyone know a cookie recipe that actually makes GOEY chewy cookies? I've managed hard, buscuity cookies. Soft but short-bready crumbly cookies. I've accidentally succeeded in making some really EXCELLENT flapjack (thanks for that recipe though Jeni!).

The key seems to be something called "all butter shortening" which Americans can't describe to me because they have never lived in a world that doesn't contain it - the Brits likewise are clueless because they've never heard of such a thing. Perhaps at the end of the day my unlitmate-recipe-search is going to be doomed to failure - I suspect I'm trying to replicate something that can only be acheived with fake additive-laden ingredients with long names.

Anyhow, the oat cookies that aren't really cookies but ARE really great are made like this.
100g butter,
100g sugar,
1tbsp golden syrup,
- melted in a pan together until caramelly and combined.

100g oats,
100g plain flour,
raisins,
- stirred in until mixed properly and then made into balls and baked briefly on greaseproof paper. Gorgeous! :)