Explain different types of eval statements? | Perl Scripting Interiew Questions

In general, there are two types of eval statements they are:
=>    Eval BLOCK and
=>    Eval EXPR
An expression is executed by eval EXPR and BLOCK is executed by eval BLOCK. Entire block is executed by eval block, BLOCK.
When you want your code passed in expression then first one is sued and to parse code in the block, second one is used.