On linux and most modern operating systems have their main memory divided into pages. It allows better utilization of memory. A page is a fixed length block of main memory, that is contiguous in both physical memory addressing and virtual memory addressing. Kernel swap and allocates memory using pages

Get the pagesize

To display size of a page in bytes, enter:

$ getconf PAGESIZE
Output:
4096 #4k

OR

$ getconf PAGE_SIZE
Output:
4096 #4k