This is the 94th most frequent Turkish word.
içerisinde
"İçerisinde" means "inside" or "within" in English.
'İçerisinde' is used to denote a time frame in which an event occurred.
Olay bir saatin içerisinde gerçekleşti.
The event happened within an hour.
In this case, 'içerisinde' describes the internal content or characteristic of the melon.
Kavunun içerisinde oldukça lezzetli bir tat vardı.
Inside the melon, there was a quite delicious flavor.
Here, 'içerisinde' indicates the location of the book being inside the bag.