This is a huge benefit. Companies provide administration, record keeping and communication of the program. Most absorb these costs. They also encourage employees to participate and will provide education and information to make it easy. 401k dollars can be invested in a wide variety of investments ranging from almost all kinds of mutual funds to individual stocks and bonds.
Companies usually offer only a handful of investment selections.
However, for the vast majority of 401k participants this is an advantage. The company uses experts to select a handful of professionally run investment alternatives such as mutual funds. This never guarantees these will turn out to be the highest earners in the future but it improves the odds. For most people this professional help supplied by the company means they can avoid the daunting task of sorting through all the possible investment options in the world. 401k's are portable.