Vector notation comprises conventions for representing vectors and distinguishing them from their scalar components.
Common forms are a bold letter 
and an arrowed letter 
. The notation 
specifies a vector whose
tail is 
and whose head is 
.
Relative to an ordered vector basis 
, ..., 
, the components 
, ..., 
are defined by
 |
The components 
depend on the chosen vector basis, not just on the
vector. They may be arranged as a row
vector or a column vector, related by transpose,
![[v_1; |; v_n]=[v_1 ... v_n]^T.](/images/equations/VectorNotation/NumberedEquation2.svg) |
For 
,
these arrangements have different matrix dimensions and
are not interchangeable in matrix multiplication.
A subscript on a bold symbol, such as 
, can instead label an entire vector
in an indexed family. Thus 
and 
need not denote the same kind of object. Other common conventions
include 
for a vector norm and a hat,
as in 
,
for a unit vector.
