# What are binaries?

To understand binaries, you need to know what bit-strings are. 

**Bit-strings** represent a contiguous sequence of bits in memory. The syntax used to denote a bit-string is `<<>>`. **`::n`** can be used to specify the number of bits used to represent a single #key# number: 8 bits by default #key#. 

A binary is a bit-string whose number of bits is​ divisible by 8.

To check whether the given bit-sequence is a binary or not, we can use the `is_binary` method:

IO.puts(is_bitstring("edpresso"))
# output: true

IO.puts(is_bitstring("edpresso"))
#output: true

IO.puts(is_bitstring(<<64::16, 128::72, 256::80>>))
#output: true

IO.puts(is_binary(<<64::16, 128::72, 256::80>>))
#output: true

IO.puts(is_bitstring(<<64::17, 128::73, 256::81>>))
#output: true

IO.puts(is_binary(<<64::17, 128::73, 256::81>>))
#output: false

ElixirEnvironment

# Observation
- A string is a UTF-8 encoded binary, where the code point for each character is encoded using 1 to 4 bytes; thus, every string is a binary.
- When the bit-string 64, 128, and 256 is represented using bits that are divisible by 8, it's a binary. 
- Whereas, the bit-string 64, 128, and 256, when represented using bits that are not divisible by 8, is not a binary.

> Since all strings are binary, using `is_binary` might be useful when you want to distinguish whether or not the input or return value is a string.  

What is is_binary in Elixir?

What are binaries?

Observation