The short answer is that certain laminate wood floors are suitable for kitchens but it is not advisable to install laminates in bathrooms.
Most laminate wood flooring come with a suitability index and will indicate if they are suitable for kitchens. Topical spills that are mopped up within 30 minutes present no problem for a laminate floor. However liquid left to stand for a few hours could cause minor to severe damage depending on the amount. Flooding will almost certainly damage your floor, both the surface and the core. Laminate separation at the boards corners is the most common form of water damage.
Another issue with spills is that they can seep in through the joints and cause water damage to the laminate locking mechanism and core. Laminate floors that are suitable for wet areas such as kitchens will come with some form of chemical impregnation in the locking mechanism as well as the core. Many floors are available with water resistant cores, but the locking mechanism might not be water resistant thus you should enquire about this.
If liquid does penetrate into the locking mechanism, it will weaken and eventually break. Liquid that penetrates the core will cause swelling and the laminate surface will separate from the core. Water damaged boards are easily replaceable. Using a skill saw, remove the affected board and replace with a new board. In most cases the new board will have to be glued in place instead of using the original locking mechanism.
Today it is common place to find laminate wood flooring in kitchens. Provided that your laminate has a suitable water resistant joint and core, and that you mop up spills without letting them stay for long periods of time, you can rest assured that there will be no issues. It is a good idea to use adhesive in the tongue and groove of the boards within a two foot radius of wet areas i.e sinks and baths. The adhesive adds additional water proofing. This can be done on glueless laminate floors for extra protection.
With regards to installing laminate floors in a bathroom, this is inadvisable. I have encountered people who have installed laminate wood flooring in bathrooms and have had many years of good use but my point of view is that it is not a good idea. There is just too much water spillage in a bathroom and no matter how careful a person is, over time there will be issues. Aside from topical water spills, heavy moisture in the air can lead to a dampening of the joints and eventual damage. Additionally, I do not know of any laminate flooring company that will warrant their floors when installed in a bathroom.