An expandable hose is quite short and compact when it's empty, but its width and length double when the hose fills with water. The expanding hose material exerts a force on the water when it expands, and this actually increases the water pressure

First of all, never leave the hose in direct sunlight unless you're actively using it to water the garden. If that's not an option, then opt for products with UV coating. The second important rule is to always drain the hose after use, especially in colder temperatures.

You can connect two expandable hoses together. There are a couple of technicalities, however. The two hoses need to have the same diameter at their opening and must have opposing male or female ends to be able to connect. If either of these issues is present, you'll have to use an adaptor.