# Sequence Alignment and the Longest Common Subsequence

Get introduced to the longest common subsequence of two strings.

## We'll cover the following

We now define an **alignment** of sequences ${v}$ and ${w}$ as a two-row matrix such that the first row contains the symbols of ${v}$ (in order), the second row contains the symbols of ${w}$ (in order), and space symbols (called **gap symbols** and shown as dashes below) may be interspersed throughout both strings, as long as two space symbols are not aligned against each other. Here is the alignment of *ATGTTATA* and *ATCGTCC* from the

Get hands-on with 1200+ tech skills courses.