When do you start to give food for baby ? Semi solid type .. And why do some parents give food at 4 months and PD say only after 6 months. Mind sharing experience on starting introducing food for baby

For me, I started my baby at 5 months old. There is no designated month to start semi solid but the baby is able to try out some semi solid food at 4 mths old. basically, mummies who want to wean off bf can do so, after 6 mths but prefer to have it as long as one an give. I gave at 5 month as I feel my baby was ready and milk alone, can't fill him up. I wanted him to have a fuller tummy when he zzz.