The current World Health Organisation and Department of Health guidelines across all four countries in the UK are that the recommended age for introducing solid foods is six months. This is because at around six months your baby will be more developmentally ready as they are able to sit up unsupported and have a good hand to mouth co-ordination. They are also better able to chew and swallow food without having to have it pureed. In addition, they are likely to be better able to absorb nutrients from a wider range of foods as their gut is developed to a stage where it is ready for solid food alongside milk.
Your baby will get most of their calories from their milk when you first offer your baby solid food at about 6 months of age. You can offer your baby their first tastes of food at a meal time, some babies may reject food at first but others may eat well from the start.