If you are self employed pensions are a tax efficient way to save .

If you are a higher rate tax payer its even better , as whatebver you put into your pension in a given tax year the Govt tops up 40% , up the amount of tax you have paid

 So you can put in 12 k say , the govt puts in 8k , and you have 20 k to invest in stocks and shares , say you go for standard blue chips like Glaxo or Vodafone , they pay 5% dividend , so you can buy more shares with that .

 eventaully after 20 years or so , you will cash in your pension and purchase an annuity , whereby a Insurance company offers to pay you a fixed some for the rest of your life , in lieu of the large sum you have depostied with them (your pension ) 

 You also get the option to draw 25% of what you saved , as a tax free lump sum ,

bear in mind you will get taxed on your pension , once you draw it , like any other income , if you draw over 10k a year (the tax allowance ) 

Although you may find you state pension puts you over the tax free limit sooner , 

 So theri are tax advanatcges to saving in a pension , and any gains you make on stocks and shares are tax free (whilst they are contained in a pension ) 

As opposed to a building society , where you will be taxed on interest , and where the rates barely keep up with inflation 

Downsides to pensions would be investing in a lot of funds where you are charged high annual charges of 1.5% say .

 You are really better getting a Self invested pension SIPP , and investing in your own choice of stocks and shares .

Alternatively there are stocks and shares ISAS , you can invest up to 12k a year in those , and pay no tax at all whilst the moiney is in the ISA wrapper .

that may be  abetter option for your freind as it is more flexible , another point to note is that , all investing shoud be done for the long term , minimum 5 years , 20 years ideally (and more )