▁project ▁don ' t ▁do ▁so ▁simultaneously , ▁and ▁matters ▁that ▁are ▁not ▁ur gent ▁can ▁be ▁discussed ▁as ynchron ously . ▁ ▁Hy brid ▁systems ▁▁ ▁There ▁is ▁also ▁another ▁possible ▁approach ▁in ▁which ▁a ▁system ▁provides ▁both ▁forms ▁of ▁communication ▁in ▁the ▁same ▁environment ▁to ▁allow ▁more ▁flex ibility ▁in ▁communication . ▁These ▁systems ▁can ▁be ▁referred ▁to ▁as ▁Hy brid ▁systems ▁where ▁messages ▁ex changed ▁usually ▁have ▁the ▁characteristics ▁of ▁asynchronous ▁messages , ▁but ▁the ▁systems ▁are ▁also ▁conce ived ▁in ▁order ▁to ▁use ▁these ▁messages ▁as ▁a ▁form ▁of ▁synchron ous ▁communication . ▁They ▁present ▁a ▁middle ▁ground ▁between ▁asynchronous ▁and ▁synchron ous ▁communication . ▁ ▁Tools ▁Communic ation ▁tools ▁for ▁G lob ally ▁Dist ributed ▁Software ▁Engineering ▁can ▁be ▁of ▁various ▁types ▁that ▁vary ▁with ▁the ▁communication ▁form ▁used , ▁the ▁interface ▁provided ▁to ▁the ▁user , ▁among ▁others . ▁Also , ▁different ▁categories ▁can ▁use ▁different ▁sens ory ▁information ▁to ▁improve ▁the ▁communication . ▁The ▁tools ▁available ▁include ▁instant ▁mess aging , ▁email , ▁audio ▁and ▁video ▁conference , ▁virtual ▁office ▁and ▁virtual ▁reality . ▁This ▁section ▁provides ▁an ▁over view ▁of ▁different ▁types ▁of ▁tools ▁and ▁some ▁popular ▁examples ▁that ▁are ▁in ▁use ▁currently , ▁however ▁it ▁is ▁not ▁a ▁thorough ▁collection ▁and ▁listing ▁of ▁available ▁tools . ▁More ▁complete ▁list ings ▁can ▁be ▁found ▁in ▁other ▁resources . ▁ ▁As ynchronous ▁tools ▁ ▁Email ▁Email ▁is ▁a ▁method ▁of ▁ex ch anging ▁digital ▁messages ▁between ▁people ▁using ▁digital ▁devices ▁such ▁as ▁computers , ▁mobile ▁ph