In the picture above, the spoon is an example of a specialist. That spoon has primarily one function, outside of meal time the spoon is not much use. A generalist is an example of the Swiss army knife it might be able to get you by at meal time but the tools that it offers might not be considered great.
On the job a specialist might be an expert in his or her field, but there range of expertise is probably limited. society tends to place a higher priority on specialists, but the thing about specialists is everything has to go right for them to be able to function. A team of specialists might work together to build a building, whereas one general contractor might be able to do a similar job.
I would recommend that people try to expand there horizons and become more of a generalist. Be a 'jack of all trades, but master of none'
https://hbr.org/2018/07/when-generalists-are-better-than-specialists-and-vice-versa
https://hbr.org/2018/07/when-generalists-are-better-than-specialists-and-vice-versa