Many families have a shower in the bathroom which may be over the bath or if the bathroom is larger it may be a separate cubicle. Some people dispense with a bath altogether and choose instead to have a larger walk-in shower or a wet room which is especially useful if there are people with mobility issues in the home.
Over time a shower cubicle can show signs of wear and tear such as door seals perishing, hinges and rollers wearing and metal plating on handles and framework delaminating. Once this is evident there really is only one solution and that is replacement.
It could be the case that the shower tray is still serviceable and so will not need replacing. This will reduce the cost of revamping your shower. Similarly, the tiles in the shower cubicle may not need replacing but may simply need regrouting. The actual shower unit may still work as it should and in this case it would be foolish to replace it unnecessarily.
The shower doors and glass panels may be the only items that will need to be replaced with new and can usually be purchased online from a bathroom supplier making sure that they are the same dimensions and the same fitting as the original ones.