Difference between proc_create and chardev access

proc is a filesystem like sysfs.
Through "proc_create" you can access the variables via (cat and echo) but character device would access the file operation like read,write etc.,
proc_create is the temporary filesystem. You can create proc for read and write as well.

In addition to Titusrathinaraj Stalins comment,

proc or sys entries are ment for debug information collection purpose. Device nodes are for actual operation on the device.
Even though you can communicate with kernel using proc or sysfs for a valid operation read/write/ are recommonded. Also there are some limitation of size and other parameters on data which we can exchange with kernel using /proc or /sys