Final answer:
The 'U' in CRUD stands for 'Update', and in SQL, the command used to update a record is the 'UPDATE' statement. This command modifies existing records in the database where a specific condition is true.
Step-by-step explanation:
The command that represents the U (update) in CRUD operations typically depends on the programming language or database being used. However, in the context of SQL, which is a widely-used language for managing and manipulating relational databases, the UPDATE statement is used for modifying existing records. For example:
UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;
This SQL command updates the data in a table by setting specific columns to new values where the specified condition is met. In other programming contexts, different methods or functions might be used, such as save(), put(), or something similar depending on the library or framework.