Arc vs Objective-C: What are the differences?
Arc: A dialect of the Lisp programming language developed by Paul Graham and Robert Morris. Arc is designed for exploratory programming: the kind where you decide what to write by writing it. A good medium for exploratory programming is one that makes programs brief and malleable, so that's what we've aimed for. This is a medium for sketching software; Objective-C: The primary programming language you use when writing software for OS X and iOS. Objective-C is a superset of the C programming language and provides object-oriented capabilities and a dynamic runtime. Objective-C inherits the syntax, primitive types, and flow control statements of C and adds syntax for defining classes and methods. It also adds language-level support for object graph management and object literals while providing dynamic typing and binding, deferring many responsibilities until runtime.
Arc and Objective-C can be primarily classified as "Languages" tools.
Uber Technologies, Instagram, and Pinterest are some of the popular companies that use Objective-C, whereas Arc is used by Helpful, Cask, and Icalia Labs. Objective-C has a broader approval, being mentioned in 851 company stacks & 363 developers stacks; compared to Arc, which is listed in 7 company stacks and 6 developer stacks.