I'm asked this frequently. What is ALM? First off, the acronym stands for Application Lifecycle Management. Here's the WikiPedia write-up on ALM but essentially, it's the process and tools your team uses to construct software. Kind of like SDLC but a whole lot more.
The best explanation of ALM (I think) comes from Eric Sink who asks and answers "What is ALM? Traceability." Yes, it's long but worth the read.
We hope to answer this and lots of other questions about software development with the new group we formed called the Central Ohio Application Lifecycle Management Group (COALMG). Check it out. We hope to see you there!