We present an organized set of stylized facts on the relations among flows of workers,changes in employment and changes in the numer of jobs at the firm level. Job turnover isusually measured by comparing stocks of employment in each firm at two points in time andadding up the absolute employment changes. This measure is a just proxy for true jobturnover because only net job changes are counted. In this paper we use information thatallows us to compare this proxy with the correct measure. We compare both of thesemeasures to a measure of labor turnover that counts movements of individuals into and outof jobs. We find that: 1) The proxy for job turnover does not differ substantially from actualjob turnover; 2) There is a big difference between job turnover and labor turnover. Mostmobility is into and out of existing jobs rather than to created or from destroyed jobs; 3) Alarge fraction of all hires are by firms where employment is declining, and a large fractionof all layoffs are by firms where employment is expanding; 4) Simultaneous hiring and firingis due to heterogeneity of the work force.