What is the difference between LR, SLR, and LALR p

Question

What is the actual difference between LR, SLR, and LALR parsers? I know that SLR and LALR are types of LR parsers, but what is the actual difference as far as their parsing tables are concerned?

And how to show whether a grammar is LR, SLR, or LALR? For an LL grammar we just have to show that any cell of the parsing table should not contain multiple production rules. Any similar rules for LALR, SLR, and LR?

For example, how can we show that the grammar

S --> Aa | bAc | dc | bda
A --> d

is LALR(1) but not SLR(1)?

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EDIT (ybungalobill): I didn't get a satisfactory answer for what's the difference between LALR and LR. So LALR's tables are smaller in size but it can recognize only a subset of LR grammars. Can someone elaborate more on the difference between LALR and LR please? LALR(1) and LR(1) will be sufficient for an answer. Both of them use 1 token look-ahead and both are table driven! How they are different?

Answer 1

One simple answer is that all LR(1) grammars are LALR(1) grammars. Compared to LALR(1), LR(1) has more states in the associated finite-state machine (more than double the states). And that is the main reason LALR(1) grammars require more code to detect syntax errors than LR(1) grammars. And one more important thing to know regarding these two grammars is that in LR(1) grammars we might have less reduce/reduce conflicts. But in LALR(1) there is more possibility of reduce/reduce conflicts.