A delayed exchange is the most common 1031 structure: the relinquished property sells first and the replacement is acquired within the 45/180-day deadlines.
In a delayed exchange the investor sells first, and a qualified intermediary holds the proceeds until the replacement property closes. The investor never has access to the funds in between. This structure gives time to find a replacement property, but the 45-day identification and 180-day closing deadlines are firm. Because most 1031 exchanges are structured this way, it is the default model for NNN buyers who are selling an existing investment property.