IC chips and datasheets
OE is Output Enable. :-)  

Logic ICs with the same number have the same functionality and pinout across manufacturers. A 74xx32 is always a quad 2-input OR gate. The technology used may be different though; a 74LS32 is low-power Schottky, while a 74HC32 is high speed CMOS. These families have their particular properties, which you'll find in a "Logic Family Guide".
Sometimes there are small differences in the details. I remember a Schmitt-Trigger inverter I once use for an oscillator, which generated a complete different frequency when using make Y instead of X. Reason: different trigger levels, these are not standardized.  

I never realized this before, but you're right: the datasheets have many terms and abbreviations which are not clearly explained. At least not in the datasheet. The datasheet often refers to the Logic Family Guide, which contains information concerning the whole series. That way they avoid datasheets becoming twice as long because they contain all this information time and again.  

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I checked with a few datasheets from different manufacturers, and I must say, it might have been worse. For many parameters there are tables with a column "symbol", and next to it a column "parameter", which describes it briefly. The "OE" appears as abbreviation in truth tables, but for what it stands for you'll have to read the ICs description.  



See also this answer about datasheets.