1. The main distinction between playmats and baby gyms is that the latter have arced bars from which fun toys bob and dangle. They're a great way to capture your baby's imagination and elicit peals of delight for when the in-laws come over. In-laws like that.
2. An important feature to consider is whether or not the arced bars can hold up your baby for his or her first attempts at standing. Most do a pretty good job, but this is a feature that we know many parents prefer.
3. The playmat, on the other hand, is simply a safe, soft, and welcoming place for the baby to roll around and discover things. These are usually marked by mirrors and toys that can be hidden in various pockets on the playmat. It's essentially a baby gym without the bars, so in many cases you should expect to pay a little less.
4. Many playmats and baby gyms tout the absence of electronics and noises in their designs. Some consider it a very good thing, and others don't. If you know you don't want whirrs, buzzes, and lullabies, be sure to double check that the one you're thinking about has no electronic components. In many cases, these things are standard for modern baby toys.
5. Some of our favorite playmats and baby gyms are from Skip Hop, Lamaze, Infantino and Fisher Price. It seems everyone designing baby products is coming out with a line of baby mats, each more creative and fun than the last.
6. For adventurous kids who like to grab and climb, an activity gym may be a better choice. This is like a baby gym, but without the playmat bottom.