what is the use of logger in spring boot code example

Example: spring log properties

logging:
  #pattern:
    #file: %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%
  file: app/application.log
  level: 
    org:
      springframework: INFO
      hibernate:
        SQL: INFO
        type:
          descriptor:
            sql:
              BasicBinder: INFO 
    web: DEBUG
    com: 
      codeswifter: DEBUG
##logging.pattern.file= %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%
  pattern:    
    console: :%d %5p [%-20.20t] %-35.35logger{15}:%-4.4L |%-15.15X{Email}|%-32.32X{UserId}| - %m%n